text: /**
   * Cesium - https://github.com/AnalyticalGraphicsInc/cesium
   *
   * Copyright 2011-2016 Cesium Contributors
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   *
   * Columbus View (Pat. Pend.)
   *
   * Portions licensed separately.
   * See https://github.com/AnalyticalGraphicsInc/cesium/blob/master/LICENSE.md for full licensing details.
   */
  if (typeof self === 'undefined') {
      self = {}; //define self so that the Dojo build can evaluate this file without crashing.
  }
  
  self.onmessage = function(event) {
      var data = event.data;
  
      require(data.loaderConfig, [data.workerModule], function(workerModule) {
          //replace onmessage with the required-in workerModule
          self.onmessage = workerModule;
      });
  };
  
  // replace setTimeout with a function that executes immediately synchronously, which
  // will make the above require synchronous like it used to be, to ensure that we we
  // have the real worker module loaded and installed before receiving any more messages.
  function setTimeout(fn) {
      fn();
  }
  
  //below is RequireJS, verbatim
  
  /** vim: et:ts=4:sw=4:sts=4
   * @license RequireJS 2.1.20 Copyright (c) 2010-2015, The Dojo Foundation All Rights Reserved.
   * Available via the MIT or new BSD license.
   * see: http://github.com/jrburke/requirejs for details
   */
  //Not using strict: uneven strict support in browsers, #392, and causes
  //problems with requirejs.exec()/transpiler plugins that may not be strict.
  /*jslint regexp: true, nomen: true, sloppy: true */
  /*global window, navigator, document, importScripts, setTimeout, opera */
  
  var requirejs, require, define;
  (function (global) {
      var req, s, head, baseElement, dataMain, src,
          interactiveScript, currentlyAddingScript, mainScript, subPath,
          version = '2.1.20',
          commentRegExp = /(\/\*([\s\S]*?)\*\/|([^:]|^)\/\/(.*)$)/mg,
          cjsRequireRegExp = /[^.]\s*require\s*\(\s*["']([^'"\s]+)["']\s*\)/g,
          jsSuffixRegExp = /\.js$/,
          currDirRegExp = /^\.\//,
          op = Object.prototype,
          ostring = op.toString,
          hasOwn = op.hasOwnProperty,
          ap = Array.prototype,
          isBrowser = !!(typeof window !== 'undefined' && typeof navigator !== 'undefined' && window.document),
          isWebWorker = !isBrowser && typeof importScripts !== 'undefined',
          //PS3 indicates loaded and complete, but need to wait for complete
          //specifically. Sequence is 'loading', 'loaded', execution,
          // then 'complete'. The UA check is unfortunate, but not sure how
          //to feature test w/o causing perf issues.
          readyRegExp = isBrowser && navigator.platform === 'PLAYSTATION 3' ?
                        /^complete$/ : /^(complete|loaded)$/,
          defContextName = '_',
          //Oh the tragedy, detecting opera. See the usage of isOpera for reason.
          isOpera = typeof opera !== 'undefined' && opera.toString() === '[object Opera]',
          contexts = {},
          cfg = {},
          globalDefQueue = [],
          useInteractive = false;
  
      function isFunction(it) {
          return ostring.call(it) === '[object Function]';
      }
  
      function isArray(it) {
          return ostring.call(it) === '[object Array]';
      }
  
      /**
       * Helper function for iterating over an array. If the func returns
       * a true value, it will break out of the loop.
       */
      function each(ary, func) {
          if (ary) {
              var i;
              for (i = 0; i < ary.length; i += 1) {
                  if (ary[i] && func(ary[i], i, ary)) {
                      break;
                  }
              }
          }
      }
  
      /**
       * Helper function for iterating over an array backwards. If the func
       * returns a true value, it will break out of the loop.
       */
      function eachReverse(ary, func) {
          if (ary) {
              var i;
              for (i = ary.length - 1; i > -1; i -= 1) {
                  if (ary[i] && func(ary[i], i, ary)) {
                      break;
                  }
              }
          }
      }
  
      function hasProp(obj, prop) {
          return hasOwn.call(obj, prop);
      }
  
      function getOwn(obj, prop) {
          return hasProp(obj, prop) && obj[prop];
      }
  
      /**
       * Cycles over properties in an object and calls a function for each
       * property value. If the function returns a truthy value, then the
       * iteration is stopped.
       */
      function eachProp(obj, func) {
          var prop;
          for (prop in obj) {
              if (hasProp(obj, prop)) {
                  if (func(obj[prop], prop)) {
                      break;
                  }
              }
          }
      }
  
      /**
       * Simple function to mix in properties from source into target,
       * but only if target does not already have a property of the same name.
       */
      function mixin(target, source, force, deepStringMixin) {
          if (source) {
              eachProp(source, function (value, prop) {
                  if (force || !hasProp(target, prop)) {
                      if (deepStringMixin && typeof value === 'object' && value &&
                          !isArray(value) && !isFunction(value) &&
                          !(value instanceof RegExp)) {
  
                          if (!target[prop]) {
                              target[prop] = {};
                          }
                          mixin(target[prop], value, force, deepStringMixin);
                      } else {
                          target[prop] = value;
                      }
                  }
              });
          }
          return target;
      }
  
      //Similar to Function.prototype.bind, but the 'this' object is specified
      //first, since it is easier to read/figure out what 'this' will be.
      function bind(obj, fn) {
          return function () {
              return fn.apply(obj, arguments);
          };
      }
  
      function scripts() {
          return document.getElementsByTagName('script');
      }
  
      function defaultOnError(err) {
          throw err;
      }
  
      //Allow getting a global that is expressed in
      //dot notation, like 'a.b.c'.
      function getGlobal(value) {
          if (!value) {
              return value;
          }
          var g = global;
          each(value.split('.'), function (part) {
              g = g[part];
          });
          return g;
      }
  
      /**
       * Constructs an error with a pointer to an URL with more information.
       * @param {String} id the error ID that maps to an ID on a web page.
       * @param {String} message human readable error.
       * @param {Error} [err] the original error, if there is one.
       *
       * @returns {Error}
       */
      function makeError(id, msg, err, requireModules) {
          var e = new Error(msg + '\nhttp://requirejs.org/docs/errors.html#' + id);
          e.requireType = id;
          e.requireModules = requireModules;
          if (err) {
              e.originalError = err;
          }
          return e;
      }
  
      if (typeof define !== 'undefined') {
          //If a define is already in play via another AMD loader,
          //do not overwrite.
          return;
      }
  
      if (typeof requirejs !== 'undefined') {
          if (isFunction(requirejs)) {
              //Do not overwrite an existing requirejs instance.
              return;
          }
          cfg = requirejs;
          requirejs = undefined;
      }
  
      //Allow for a require config object
      if (typeof require !== 'undefined' && !isFunction(require)) {
          //assume it is a config object.
          cfg = require;
          require = undefined;
      }
  
      function newContext(contextName) {
          var inCheckLoaded, Module, context, handlers,
              checkLoadedTimeoutId,
              config = {
                  //Defaults. Do not set a default for map
                  //config to speed up normalize(), which
                  //will run faster if there is no default.
                  waitSeconds: 7,
                  baseUrl: './',
                  paths: {},
                  bundles: {},
                  pkgs: {},
                  shim: {},
                  config: {}
              },
              registry = {},
              //registry of just enabled modules, to speed
              //cycle breaking code when lots of modules
              //are registered, but not activated.
              enabledRegistry = {},
              undefEvents = {},
              defQueue = [],
              defined = {},
              urlFetched = {},
              bundlesMap = {},
              requireCounter = 1,
              unnormalizedCounter = 1;
  
          /**
           * Trims the . and .. from an array of path segments.
           * It will keep a leading path segment if a .. will become
           * the first path segment, to help with module name lookups,
           * which act like paths, but can be remapped. But the end result,
           * all paths that use this function should look normalized.
           * NOTE: this method MODIFIES the input array.
           * @param {Array} ary the array of path segments.
           */
          function trimDots(ary) {
              var i, part;
              for (i = 0; i < ary.length; i++) {
                  part = ary[i];
                  if (part === '.') {
                      ary.splice(i, 1);
                      i -= 1;
                  } else if (part === '..') {
                      // If at the start, or previous value is still ..,
                      // keep them so that when converted to a path it may
                      // still work when converted to a path, even though
                      // as an ID it is less than ideal. In larger point
                      // releases, may be better to just kick out an error.
                      if (i === 0 || (i === 1 && ary[2] === '..') || ary[i - 1] === '..') {
                          continue;
                      } else if (i > 0) {
                          ary.splice(i - 1, 2);
                          i -= 2;
                      }
                  }
              }
          }
  
          /**
           * Given a relative module name, like ./something, normalize it to
           * a real name that can be mapped to a path.
           * @param {String} name the relative name
           * @param {String} baseName a real name that the name arg is relative
           * to.
           * @param {Boolean} applyMap apply the map config to the value. Should
           * only be done if this normalization is for a dependency ID.
           * @returns {String} normalized name
           */
          function normalize(name, baseName, applyMap) {
              var pkgMain, mapValue, nameParts, i, j, nameSegment, lastIndex,
                  foundMap, foundI, foundStarMap, starI, normalizedBaseParts,
                  baseParts = (baseName && baseName.split('/')),
                  map = config.map,
                  starMap = map && map['*'];
  
              //Adjust any relative paths.
              if (name) {
                  name = name.split('/');
                  lastIndex = name.length - 1;
  
                  // If wanting node ID compatibility, strip .js from end
                  // of IDs. Have to do this here, and not in nameToUrl
                  // because node allows either .js or non .js to map
                  // to same file.
                  if (config.nodeIdCompat && jsSuffixRegExp.test(name[lastIndex])) {
                      name[lastIndex] = name[lastIndex].replace(jsSuffixRegExp, '');
                  }
  
                  // Starts with a '.' so need the baseName
                  if (name[0].charAt(0) === '.' && baseParts) {
                      //Convert baseName to array, and lop off the last part,
                      //so that . matches that 'directory' and not name of the baseName's
                      //module. For instance, baseName of 'one/two/three', maps to
                      //'one/two/three.js', but we want the directory, 'one/two' for
                      //this normalization.
                      normalizedBaseParts = baseParts.slice(0, baseParts.length - 1);
                      name = normalizedBaseParts.concat(name);
                  }
  
                  trimDots(name);
                  name = name.join('/');
              }
  
              //Apply map config if available.
              if (applyMap && map && (baseParts || starMap)) {
                  nameParts = name.split('/');
  
                  outerLoop: for (i = nameParts.length; i > 0; i -= 1) {
                      nameSegment = nameParts.slice(0, i).join('/');
  
                      if (baseParts) {
                          //Find the longest baseName segment match in the config.
                          //So, do joins on the biggest to smallest lengths of baseParts.
                          for (j = baseParts.length; j > 0; j -= 1) {
                              mapValue = getOwn(map, baseParts.slice(0, j).join('/'));
  
                              //baseName segment has config, find if it has one for
                              //this name.
                              if (mapValue) {
                                  mapValue = getOwn(mapValue, nameSegment);
                                  if (mapValue) {
                                      //Match, update name to the new value.
                                      foundMap = mapValue;
                                      foundI = i;
                                      break outerLoop;
                                  }
                              }
                          }
                      }
  
                      //Check for a star map match, but just hold on to it,
                      //if there is a shorter segment match later in a matching
                      //config, then favor over this star map.
                      if (!foundStarMap && starMap && getOwn(starMap, nameSegment)) {
                          foundStarMap = getOwn(starMap, nameSegment);
                          starI = i;
                      }
                  }
  
                  if (!foundMap && foundStarMap) {
                      foundMap = foundStarMap;
                      foundI = starI;
                  }
  
                  if (foundMap) {
                      nameParts.splice(0, foundI, foundMap);
                      name = nameParts.join('/');
                  }
              }
  
              // If the name points to a package's name, use
              // the package main instead.
              pkgMain = getOwn(config.pkgs, name);
  
              return pkgMain ? pkgMain : name;
          }
  
          function removeScript(name) {
              if (isBrowser) {
                  each(scripts(), function (scriptNode) {
                      if (scriptNode.getAttribute('data-requiremodule') === name &&
                              scriptNode.getAttribute('data-requirecontext') === context.contextName) {
                          scriptNode.parentNode.removeChild(scriptNode);
                          return true;
                      }
                  });
              }
          }
  
          function hasPathFallback(id) {
              var pathConfig = getOwn(config.paths, id);
              if (pathConfig && isArray(pathConfig) && pathConfig.length > 1) {
                  //Pop off the first array value, since it failed, and
                  //retry
                  pathConfig.shift();
                  context.require.undef(id);
  
                  //Custom require that does not do map translation, since
                  //ID is "absolute", already mapped/resolved.
                  context.makeRequire(null, {
                      skipMap: true
                  })([id]);
  
                  return true;
              }
          }
  
          //Turns a plugin!resource to [plugin, resource]
          //with the plugin being undefined if the name
          //did not have a plugin prefix.
          function splitPrefix(name) {
              var prefix,
                  index = name ? name.indexOf('!') : -1;
              if (index > -1) {
                  prefix = name.substring(0, index);
                  name = name.substring(index + 1, name.length);
              }
              return [prefix, name];
          }
  
          /**
           * Creates a module mapping that includes plugin prefix, module
           * name, and path. If parentModuleMap is provided it will
           * also normalize the name via require.normalize()
           *
           * @param {String} name the module name
           * @param {String} [parentModuleMap] parent module map
           * for the module name, used to resolve relative names.
           * @param {Boolean} isNormalized: is the ID already normalized.
           * This is true if this call is done for a define() module ID.
           * @param {Boolean} applyMap: apply the map config to the ID.
           * Should only be true if this map is for a dependency.
           *
           * @returns {Object}
           */
          function makeModuleMap(name, parentModuleMap, isNormalized, applyMap) {
              var url, pluginModule, suffix, nameParts,
                  prefix = null,
                  parentName = parentModuleMap ? parentModuleMap.name : null,
                  originalName = name,
                  isDefine = true,
                  normalizedName = '';
  
              //If no name, then it means it is a require call, generate an
              //internal name.
              if (!name) {
                  isDefine = false;
                  name = '_@r' + (requireCounter += 1);
              }
  
              nameParts = splitPrefix(name);
              prefix = nameParts[0];
              name = nameParts[1];
  
              if (prefix) {
                  prefix = normalize(prefix, parentName, applyMap);
                  pluginModule = getOwn(defined, prefix);
              }
  
              //Account for relative paths if there is a base name.
              if (name) {
                  if (prefix) {
                      if (pluginModule && pluginModule.normalize) {
                          //Plugin is loaded, use its normalize method.
                          normalizedName = pluginModule.normalize(name, function (name) {
                              return normalize(name, parentName, applyMap);
                          });
                      } else {
                          // If nested plugin references, then do not try to
                          // normalize, as it will not normalize correctly. This
                          // places a restriction on resourceIds, and the longer
                          // term solution is not to normalize until plugins are
                          // loaded and all normalizations to allow for async
                          // loading of a loader plugin. But for now, fixes the
                          // common uses. Details in #1131
                          normalizedName = name.indexOf('!') === -1 ?
                                           normalize(name, parentName, applyMap) :
                                           name;
                      }
                  } else {
                      //A regular module.
                      normalizedName = normalize(name, parentName, applyMap);
  
                      //Normalized name may be a plugin ID due to map config
                      //application in normalize. The map config values must
                      //already be normalized, so do not need to redo that part.
                      nameParts = splitPrefix(normalizedName);
                      prefix = nameParts[0];
                      normalizedName = nameParts[1];
                      isNormalized = true;
  
                      url = context.nameToUrl(normalizedName);
                  }
              }
  
              //If the id is a plugin id that cannot be determined if it needs
              //normalization, stamp it with a unique ID so two matching relative
              //ids that may conflict can be separate.
              suffix = prefix && !pluginModule && !isNormalized ?
                       '_unnormalized' + (unnormalizedCounter += 1) :
                       '';
  
              return {
                  prefix: prefix,
                  name: normalizedName,
                  parentMap: parentModuleMap,
                  unnormalized: !!suffix,
                  url: url,
                  originalName: originalName,
                  isDefine: isDefine,
                  id: (prefix ?
                          prefix + '!' + normalizedName :
                          normalizedName) + suffix
              };
          }
  
          function getModule(depMap) {
              var id = depMap.id,
                  mod = getOwn(registry, id);
  
              if (!mod) {
                  mod = registry[id] = new context.Module(depMap);
              }
  
              return mod;
          }
  
          function on(depMap, name, fn) {
              var id = depMap.id,
                  mod = getOwn(registry, id);
  
              if (hasProp(defined, id) &&
                      (!mod || mod.defineEmitComplete)) {
                  if (name === 'defined') {
                      fn(defined[id]);
                  }
              } else {
                  mod = getModule(depMap);
                  if (mod.error && name === 'error') {
                      fn(mod.error);
                  } else {
                      mod.on(name, fn);
                  }
              }
          }
  
          function onError(err, errback) {
              var ids = err.requireModules,
                  notified = false;
  
              if (errback) {
                  errback(err);
              } else {
                  each(ids, function (id) {
                      var mod = getOwn(registry, id);
                      if (mod) {
                          //Set error on module, so it skips timeout checks.
                          mod.error = err;
                          if (mod.events.error) {
                              notified = true;
                              mod.emit('error', err);
                          }
                      }
                  });
  
                  if (!notified) {
                      req.onError(err);
                  }
              }
          }
  
          /**
           * Internal method to transfer globalQueue items to this context's
           * defQueue.
           */
          function takeGlobalQueue() {
              //Push all the globalDefQueue items into the context's defQueue
              if (globalDefQueue.length) {
                  each(globalDefQueue, function(queueItem) {
                      var id = queueItem[0];
                      if (typeof id === 'string') {
                          context.defQueueMap[id] = true;
                      }
                      defQueue.push(queueItem);
                  });
                  globalDefQueue = [];
              }
          }
  
          handlers = {
              'require': function (mod) {
                  if (mod.require) {
                      return mod.require;
                  } else {
                      return (mod.require = context.makeRequire(mod.map));
                  }
              },
              'exports': function (mod) {
                  mod.usingExports = true;
                  if (mod.map.isDefine) {
                      if (mod.exports) {
                          return (defined[mod.map.id] = mod.exports);
                      } else {
                          return (mod.exports = defined[mod.map.id] = {});
                      }
                  }
              },
              'module': function (mod) {
                  if (mod.module) {
                      return mod.module;
                  } else {
                      return (mod.module = {
                          id: mod.map.id,
                          uri: mod.map.url,
                          config: function () {
                              return getOwn(config.config, mod.map.id) || {};
                          },
                          exports: mod.exports || (mod.exports = {})
                      });
                  }
              }
          };
  
          function cleanRegistry(id) {
              //Clean up machinery used for waiting modules.
              delete registry[id];
              delete enabledRegistry[id];
          }
  
          function breakCycle(mod, traced, processed) {
              var id = mod.map.id;
  
              if (mod.error) {
                  mod.emit('error', mod.error);
              } else {
                  traced[id] = true;
                  each(mod.depMaps, function (depMap, i) {
                      var depId = depMap.id,
                          dep = getOwn(registry, depId);
  
                      //Only force things that have not completed
                      //being defined, so still in the registry,
                      //and only if it has not been matched up
                      //in the module already.
                      if (dep && !mod.depMatched[i] && !processed[depId]) {
                          if (getOwn(traced, depId)) {
                              mod.defineDep(i, defined[depId]);
                              mod.check(); //pass false?
                          } else {
                              breakCycle(dep, traced, processed);
                          }
                      }
                  });
                  processed[id] = true;
              }
          }
  
          function checkLoaded() {
              var err, usingPathFallback,
                  waitInterval = config.waitSeconds * 1000,
                  //It is possible to disable the wait interval by using waitSeconds of 0.
                  expired = waitInterval && (context.startTime + waitInterval) < new Date().getTime(),
                  noLoads = [],
                  reqCalls = [],
                  stillLoading = false,
                  needCycleCheck = true;
  
              //Do not bother if this call was a result of a cycle break.
              if (inCheckLoaded) {
                  return;
              }
  
              inCheckLoaded = true;
  
              //Figure out the state of all the modules.
              eachProp(enabledRegistry, function (mod) {
                  var map = mod.map,
                      modId = map.id;
  
                  //Skip things that are not enabled or in error state.
                  if (!mod.enabled) {
                      return;
                  }
  
                  if (!map.isDefine) {
                      reqCalls.push(mod);
                  }
  
                  if (!mod.error) {
                      //If the module should be executed, and it has not
                      //been inited and time is up, remember it.
                      if (!mod.inited && expired) {
                          if (hasPathFallback(modId)) {
                              usingPathFallback = true;
                              stillLoading = true;
                          } else {
                              noLoads.push(modId);
                              removeScript(modId);
                          }
                      } else if (!mod.inited && mod.fetched && map.isDefine) {
                          stillLoading = true;
                          if (!map.prefix) {
                              //No reason to keep looking for unfinished
                              //loading. If the only stillLoading is a
                              //plugin resource though, keep going,
                              //because it may be that a plugin resource
                              //is waiting on a non-plugin cycle.
                              return (needCycleCheck = false);
                          }
                      }
                  }
              });
  
              if (expired && noLoads.length) {
                  //If wait time expired, throw error of unloaded modules.
                  err = makeError('timeout', 'Load timeout for modules: ' + noLoads, null, noLoads);
                  err.contextName = context.contextName;
                  return onError(err);
              }
  
              //Not expired, check for a cycle.
              if (needCycleCheck) {
                  each(reqCalls, function (mod) {
                      breakCycle(mod, {}, {});
                  });
              }
  
              //If still waiting on loads, and the waiting load is something
              //other than a plugin resource, or there are still outstanding
              //scripts, then just try back later.
              if ((!expired || usingPathFallback) && stillLoading) {
                  //Something is still waiting to load. Wait for it, but only
                  //if a timeout is not already in effect.
                  if ((isBrowser || isWebWorker) && !checkLoadedTimeoutId) {
                      checkLoadedTimeoutId = setTimeout(function () {
                          checkLoadedTimeoutId = 0;
                          checkLoaded();
                      }, 50);
                  }
              }
  
              inCheckLoaded = false;
          }
  
          Module = function (map) {
              this.events = getOwn(undefEvents, map.id) || {};
              this.map = map;
              this.shim = getOwn(config.shim, map.id);
              this.depExports = [];
              this.depMaps = [];
              this.depMatched = [];
              this.pluginMaps = {};
              this.depCount = 0;
  
              /* this.exports this.factory
                 this.depMaps = [],
                 this.enabled, this.fetched
              */
          };
  
          Module.prototype = {
              init: function (depMaps, factory, errback, options) {
                  options = options || {};
  
                  //Do not do more inits if already done. Can happen if there
                  //are multiple define calls for the same module. That is not
                  //a normal, common case, but it is also not unexpected.
                  if (this.inited) {
                      return;
                  }
  
                  this.factory = factory;
  
                  if (errback) {
                      //Register for errors on this module.
                      this.on('error', errback);
                  } else if (this.events.error) {
                      //If no errback already, but there are error listeners
                      //on this module, set up an errback to pass to the deps.
                      errback = bind(this, function (err) {
                          this.emit('error', err);
                      });
                  }
  
                  //Do a copy of the dependency array, so that
                  //source inputs are not modified. For example
                  //"shim" deps are passed in here directly, and
                  //doing a direct modification of the depMaps array
                  //would affect that config.
                  this.depMaps = depMaps && depMaps.slice(0);
  
                  this.errback = errback;
  
                  //Indicate this module has be initialized
                  this.inited = true;
  
                  this.ignore = options.ignore;
  
                  //Could have option to init this module in enabled mode,
                  //or could have been previously marked as enabled. However,
                  //the dependencies are not known until init is called. So
                  //if enabled previously, now trigger dependencies as enabled.
                  if (options.enabled || this.enabled) {
                      //Enable this module and dependencies.
                      //Will call this.check()
                      this.enable();
                  } else {
                      this.check();
                  }
              },
  
              defineDep: function (i, depExports) {
                  //Because of cycles, defined callback for a given
                  //export can be called more than once.
                  if (!this.depMatched[i]) {
                      this.depMatched[i] = true;
                      this.depCount -= 1;
                      this.depExports[i] = depExports;
                  }
              },
  
              fetch: function () {
                  if (this.fetched) {
                      return;
                  }
                  this.fetched = true;
  
                  context.startTime = (new Date()).getTime();
  
                  var map = this.map;
  
                  //If the manager is for a plugin managed resource,
                  //ask the plugin to load it now.
                  if (this.shim) {
                      context.makeRequire(this.map, {
                          enableBuildCallback: true
                      })(this.shim.deps || [], bind(this, function () {
                          return map.prefix ? this.callPlugin() : this.load();
                      }));
                  } else {
                      //Regular dependency.
                      return map.prefix ? this.callPlugin() : this.load();
                  }
              },
  
              load: function () {
                  var url = this.map.url;
  
                  //Regular dependency.
                  if (!urlFetched[url]) {
                      urlFetched[url] = true;
                      context.load(this.map.id, url);
                  }
              },
  
              /**
               * Checks if the module is ready to define itself, and if so,
               * define it.
               */
              check: function () {
                  if (!this.enabled || this.enabling) {
                      return;
                  }
  
                  var err, cjsModule,
                      id = this.map.id,
                      depExports = this.depExports,
                      exports = this.exports,
                      factory = this.factory;
  
                  if (!this.inited) {
                      // Only fetch if not already in the defQueue.
                      if (!hasProp(context.defQueueMap, id)) {
                          this.fetch();
                      }
                  } else if (this.error) {
                      this.emit('error', this.error);
                  } else if (!this.defining) {
                      //The factory could trigger another require call
                      //that would result in checking this module to
                      //define itself again. If already in the process
                      //of doing that, skip this work.
                      this.defining = true;
  
                      if (this.depCount < 1 && !this.defined) {
                          if (isFunction(factory)) {
                              //If there is an error listener, favor passing
                              //to that instead of throwing an error. However,
                              //only do it for define()'d  modules. require
                              //errbacks should not be called for failures in
                              //their callbacks (#699). However if a global
                              //onError is set, use that.
                              if ((this.events.error && this.map.isDefine) ||
                                  req.onError !== defaultOnError) {
                                  try {
                                      exports = context.execCb(id, factory, depExports, exports);
                                  } catch (e) {
                                      err = e;
                                  }
                              } else {
                                  exports = context.execCb(id, factory, depExports, exports);
                              }
  
                              // Favor return value over exports. If node/cjs in play,
                              // then will not have a return value anyway. Favor
                              // module.exports assignment over exports object.
                              if (this.map.isDefine && exports === undefined) {
                                  cjsModule = this.module;
                                  if (cjsModule) {
                                      exports = cjsModule.exports;
                                  } else if (this.usingExports) {
                                      //exports already set the defined value.
                                      exports = this.exports;
                                  }
                              }
  
                              if (err) {
                                  err.requireMap = this.map;
                                  err.requireModules = this.map.isDefine ? [this.map.id] : null;
                                  err.requireType = this.map.isDefine ? 'define' : 'require';
                                  return onError((this.error = err));
                              }
  
                          } else {
                              //Just a literal value
                              exports = factory;
                          }
  
                          this.exports = exports;
  
                          if (this.map.isDefine && !this.ignore) {
                              defined[id] = exports;
  
                              if (req.onResourceLoad) {
                                  req.onResourceLoad(context, this.map, this.depMaps);
                              }
                          }
  
                          //Clean up
                          cleanRegistry(id);
  
                          this.defined = true;
                      }
  
                      //Finished the define stage. Allow calling check again
                      //to allow define notifications below in the case of a
                      //cycle.
                      this.defining = false;
  
                      if (this.defined && !this.defineEmitted) {
                          this.defineEmitted = true;
                          this.emit('defined', this.exports);
                          this.defineEmitComplete = true;
                      }
  
                  }
              },
  
              callPlugin: function () {
                  var map = this.map,
                      id = map.id,
                      //Map already normalized the prefix.
                      pluginMap = makeModuleMap(map.prefix);
  
                  //Mark this as a dependency for this plugin, so it
                  //can be traced for cycles.
                  this.depMaps.push(pluginMap);
  
                  on(pluginMap, 'defined', bind(this, function (plugin) {
                      var load, normalizedMap, normalizedMod,
                          bundleId = getOwn(bundlesMap, this.map.id),
                          name = this.map.name,
                          parentName = this.map.parentMap ? this.map.parentMap.name : null,
                          localRequire = context.makeRequire(map.parentMap, {
                              enableBuildCallback: true
                          });
  
                      //If current map is not normalized, wait for that
                      //normalized name to load instead of continuing.
                      if (this.map.unnormalized) {
                          //Normalize the ID if the plugin allows it.
                          if (plugin.normalize) {
                              name = plugin.normalize(name, function (name) {
                                  return normalize(name, parentName, true);
                              }) || '';
                          }
  
                          //prefix and name should already be normalized, no need
                          //for applying map config again either.
                          normalizedMap = makeModuleMap(map.prefix + '!' + name,
                                                        this.map.parentMap);
                          on(normalizedMap,
                              'defined', bind(this, function (value) {
                                  this.init([], function () { return value; }, null, {
                                      enabled: true,
                                      ignore: true
                                  });
                              }));
  
                          normalizedMod = getOwn(registry, normalizedMap.id);
                          if (normalizedMod) {
                              //Mark this as a dependency for this plugin, so it
                              //can be traced for cycles.
                              this.depMaps.push(normalizedMap);
  
                              if (this.events.error) {
                                  normalizedMod.on('error', bind(this, function (err) {
                                      this.emit('error', err);
                                  }));
                              }
                              normalizedMod.enable();
                          }
  
                          return;
                      }
  
                      //If a paths config, then just load that file instead to
                      //resolve the plugin, as it is built into that paths layer.
                      if (bundleId) {
                          this.map.url = context.nameToUrl(bundleId);
                          this.load();
                          return;
                      }
  
                      load = bind(this, function (value) {
                          this.init([], function () { return value; }, null, {
                              enabled: true
                          });
                      });
  
                      load.error = bind(this, function (err) {
                          this.inited = true;
                          this.error = err;
                          err.requireModules = [id];
  
                          //Remove temp unnormalized modules for this module,
                          //since they will never be resolved otherwise now.
                          eachProp(registry, function (mod) {
                              if (mod.map.id.indexOf(id + '_unnormalized') === 0) {
                                  cleanRegistry(mod.map.id);
                              }
                          });
  
                          onError(err);
                      });
  
                      //Allow plugins to load other code without having to know the
                      //context or how to 'complete' the load.
                      load.fromText = bind(this, function (text, textAlt) {
                          /*jslint evil: true */
                          var moduleName = map.name,
                              moduleMap = makeModuleMap(moduleName),
                              hasInteractive = useInteractive;
  
                          //As of 2.1.0, support just passing the text, to reinforce
                          //fromText only being called once per resource. Still
                          //support old style of passing moduleName but discard
                          //that moduleName in favor of the internal ref.
                          if (textAlt) {
                              text = textAlt;
                          }
  
                          //Turn off interactive script matching for IE for any define
                          //calls in the text, then turn it back on at the end.
                          if (hasInteractive) {
                              useInteractive = false;
                          }
  
                          //Prime the system by creating a module instance for
                          //it.
                          getModule(moduleMap);
  
                          //Transfer any config to this other module.
                          if (hasProp(config.config, id)) {
                              config.config[moduleName] = config.config[id];
                          }
  
                          try {
                              req.exec(text);
                          } catch (e) {
                              return onError(makeError('fromtexteval',
                                               'fromText eval for ' + id +
                                              ' failed: ' + e,
                                               e,
                                               [id]));
                          }
  
                          if (hasInteractive) {
                              useInteractive = true;
                          }
  
                          //Mark this as a dependency for the plugin
                          //resource
                          this.depMaps.push(moduleMap);
  
                          //Support anonymous modules.
                          context.completeLoad(moduleName);
  
                          //Bind the value of that module to the value for this
                          //resource ID.
                          localRequire([moduleName], load);
                      });
  
                      //Use parentName here since the plugin's name is not reliable,
                      //could be some weird string with no path that actually wants to
                      //reference the parentName's path.
                      plugin.load(map.name, localRequire, load, config);
                  }));
  
                  context.enable(pluginMap, this);
                  this.pluginMaps[pluginMap.id] = pluginMap;
              },
  
              enable: function () {
                  enabledRegistry[this.map.id] = this;
                  this.enabled = true;
  
                  //Set flag mentioning that the module is enabling,
                  //so that immediate calls to the defined callbacks
                  //for dependencies do not trigger inadvertent load
                  //with the depCount still being zero.
                  this.enabling = true;
  
                  //Enable each dependency
                  each(this.depMaps, bind(this, function (depMap, i) {
                      var id, mod, handler;
  
                      if (typeof depMap === 'string') {
                          //Dependency needs to be converted to a depMap
                          //and wired up to this module.
                          depMap = makeModuleMap(depMap,
                                                 (this.map.isDefine ? this.map : this.map.parentMap),
                                                 false,
                                                 !this.skipMap);
                          this.depMaps[i] = depMap;
  
                          handler = getOwn(handlers, depMap.id);
  
                          if (handler) {
                              this.depExports[i] = handler(this);
                              return;
                          }
  
                          this.depCount += 1;
  
                          on(depMap, 'defined', bind(this, function (depExports) {
                              if (this.undefed) {
                                  return;
                              }
                              this.defineDep(i, depExports);
                              this.check();
                          }));
  
                          if (this.errback) {
                              on(depMap, 'error', bind(this, this.errback));
                          } else if (this.events.error) {
                              // No direct errback on this module, but something
                              // else is listening for errors, so be sure to
                              // propagate the error correctly.
                              on(depMap, 'error', bind(this, function(err) {
                                  this.emit('error', err);
                              }));
                          }
                      }
  
                      id = depMap.id;
                      mod = registry[id];
  
                      //Skip special modules like 'require', 'exports', 'module'
                      //Also, don't call enable if it is already enabled,
                      //important in circular dependency cases.
                      if (!hasProp(handlers, id) && mod && !mod.enabled) {
                          context.enable(depMap, this);
                      }
                  }));
  
                  //Enable each plugin that is used in
                  //a dependency
                  eachProp(this.pluginMaps, bind(this, function (pluginMap) {
                      var mod = getOwn(registry, pluginMap.id);
                      if (mod && !mod.enabled) {
                          context.enable(pluginMap, this);
                      }
                  }));
  
                  this.enabling = false;
  
                  this.check();
              },
  
              on: function (name, cb) {
                  var cbs = this.events[name];
                  if (!cbs) {
                      cbs = this.events[name] = [];
                  }
                  cbs.push(cb);
              },
  
              emit: function (name, evt) {
                  each(this.events[name], function (cb) {
                      cb(evt);
                  });
                  if (name === 'error') {
                      //Now that the error handler was triggered, remove
                      //the listeners, since this broken Module instance
                      //can stay around for a while in the registry.
                      delete this.events[name];
                  }
              }
          };
  
          function callGetModule(args) {
              //Skip modules already defined.
              if (!hasProp(defined, args[0])) {
                  getModule(makeModuleMap(args[0], null, true)).init(args[1], args[2]);
              }
          }
  
          function removeListener(node, func, name, ieName) {
              //Favor detachEvent because of IE9
              //issue, see attachEvent/addEventListener comment elsewhere
              //in this file.
              if (node.detachEvent && !isOpera) {
                  //Probably IE. If not it will throw an error, which will be
                  //useful to know.
                  if (ieName) {
                      node.detachEvent(ieName, func);
                  }
              } else {
                  node.removeEventListener(name, func, false);
              }
          }
  
          /**
           * Given an event from a script node, get the requirejs info from it,
           * and then removes the event listeners on the node.
           * @param {Event} evt
           * @returns {Object}
           */
          function getScriptData(evt) {
              //Using currentTarget instead of target for Firefox 2.0's sake. Not
              //all old browsers will be supported, but this one was easy enough
              //to support and still makes sense.
              var node = evt.currentTarget || evt.srcElement;
  
              //Remove the listeners once here.
              removeListener(node, context.onScriptLoad, 'load', 'onreadystatechange');
              removeListener(node, context.onScriptError, 'error');
  
              return {
                  node: node,
                  id: node && node.getAttribute('data-requiremodule')
              };
          }
  
          function intakeDefines() {
              var args;
  
              //Any defined modules in the global queue, intake them now.
              takeGlobalQueue();
  
              //Make sure any remaining defQueue items get properly processed.
              while (defQueue.length) {
                  args = defQueue.shift();
                  if (args[0] === null) {
                      return onError(makeError('mismatch', 'Mismatched anonymous define() module: ' +
                          args[args.length - 1]));
                  } else {
                      //args are id, deps, factory. Should be normalized by the
                      //define() function.
                      callGetModule(args);
                  }
              }
              context.defQueueMap = {};
          }
  
          context = {
              config: config,
              contextName: contextName,
              registry: registry,
              defined: defined,
              urlFetched: urlFetched,
              defQueue: defQueue,
              defQueueMap: {},
              Module: Module,
              makeModuleMap: makeModuleMap,
              nextTick: req.nextTick,
              onError: onError,
  
              /**
               * Set a configuration for the context.
               * @param {Object} cfg config object to integrate.
               */
              configure: function (cfg) {
                  //Make sure the baseUrl ends in a slash.
                  if (cfg.baseUrl) {
                      if (cfg.baseUrl.charAt(cfg.baseUrl.length - 1) !== '/') {
                          cfg.baseUrl += '/';
                      }
                  }
  
                  //Save off the paths since they require special processing,
                  //they are additive.
                  var shim = config.shim,
                      objs = {
                          paths: true,
                          bundles: true,
                          config: true,
                          map: true
                      };
  
                  eachProp(cfg, function (value, prop) {
                      if (objs[prop]) {
                          if (!config[prop]) {
                              config[prop] = {};
                          }
                          mixin(config[prop], value, true, true);
                      } else {
                          config[prop] = value;
                      }
                  });
  
                  //Reverse map the bundles
                  if (cfg.bundles) {
                      eachProp(cfg.bundles, function (value, prop) {
                          each(value, function (v) {
                              if (v !== prop) {
                                  bundlesMap[v] = prop;
                              }
                          });
                      });
                  }
  
                  //Merge shim
                  if (cfg.shim) {
                      eachProp(cfg.shim, function (value, id) {
                          //Normalize the structure
                          if (isArray(value)) {
                              value = {
                                  deps: value
                              };
                          }
                          if ((value.exports || value.init) && !value.exportsFn) {
                              value.exportsFn = context.makeShimExports(value);
                          }
                          shim[id] = value;
                      });
                      config.shim = shim;
                  }
  
                  //Adjust packages if necessary.
                  if (cfg.packages) {
                      each(cfg.packages, function (pkgObj) {
                          var location, name;
  
                          pkgObj = typeof pkgObj === 'string' ? {name: pkgObj} : pkgObj;
  
                          name = pkgObj.name;
                          location = pkgObj.location;
                          if (location) {
                              config.paths[name] = pkgObj.location;
                          }
  
                          //Save pointer to main module ID for pkg name.
                          //Remove leading dot in main, so main paths are normalized,
                          //and remove any trailing .js, since different package
                          //envs have different conventions: some use a module name,
                          //some use a file name.
                          config.pkgs[name] = pkgObj.name + '/' + (pkgObj.main || 'main')
                                       .replace(currDirRegExp, '')
                                       .replace(jsSuffixRegExp, '');
                      });
                  }
  
                  //If there are any "waiting to execute" modules in the registry,
                  //update the maps for them, since their info, like URLs to load,
                  //may have changed.
                  eachProp(registry, function (mod, id) {
                      //If module already has init called, since it is too
                      //late to modify them, and ignore unnormalized ones
                      //since they are transient.
                      if (!mod.inited && !mod.map.unnormalized) {
                          mod.map = makeModuleMap(id, null, true);
                      }
                  });
  
                  //If a deps array or a config callback is specified, then call
                  //require with those args. This is useful when require is defined as a
                  //config object before require.js is loaded.
                  if (cfg.deps || cfg.callback) {
                      context.require(cfg.deps || [], cfg.callback);
                  }
              },
  
              makeShimExports: function (value) {
                  function fn() {
                      var ret;
                      if (value.init) {
                          ret = value.init.apply(global, arguments);
                      }
                      return ret || (value.exports && getGlobal(value.exports));
                  }
                  return fn;
              },
  
              makeRequire: function (relMap, options) {
                  options = options || {};
  
                  function localRequire(deps, callback, errback) {
                      var id, map, requireMod;
  
                      if (options.enableBuildCallback && callback && isFunction(callback)) {
                          callback.__requireJsBuild = true;
                      }
  
                      if (typeof deps === 'string') {
                          if (isFunction(callback)) {
                              //Invalid call
                              return onError(makeError('requireargs', 'Invalid require call'), errback);
                          }
  
                          //If require|exports|module are requested, get the
                          //value for them from the special handlers. Caveat:
                          //this only works while module is being defined.
                          if (relMap && hasProp(handlers, deps)) {
                              return handlers[deps](registry[relMap.id]);
                          }
  
                          //Synchronous access to one module. If require.get is
                          //available (as in the Node adapter), prefer that.
                          if (req.get) {
                              return req.get(context, deps, relMap, localRequire);
                          }
  
                          //Normalize module name, if it contains . or ..
                          map = makeModuleMap(deps, relMap, false, true);
                          id = map.id;
  
                          if (!hasProp(defined, id)) {
                              return onError(makeError('notloaded', 'Module name "' +
                                          id +
                                          '" has not been loaded yet for context: ' +
                                          contextName +
                                          (relMap ? '' : '. Use require([])')));
                          }
                          return defined[id];
                      }
  
                      //Grab defines waiting in the global queue.
                      intakeDefines();
  
                      //Mark all the dependencies as needing to be loaded.
                      context.nextTick(function () {
                          //Some defines could have been added since the
                          //require call, collect them.
                          intakeDefines();
  
                          requireMod = getModule(makeModuleMap(null, relMap));
  
                          //Store if map config should be applied to this require
                          //call for dependencies.
                          requireMod.skipMap = options.skipMap;
  
                          requireMod.init(deps, callback, errback, {
                              enabled: true
                          });
  
                          checkLoaded();
                      });
  
                      return localRequire;
                  }
  
                  mixin(localRequire, {
                      isBrowser: isBrowser,
  
                      /**
                       * Converts a module name + .extension into an URL path.
                       * *Requires* the use of a module name. It does not support using
                       * plain URLs like nameToUrl.
                       */
                      toUrl: function (moduleNamePlusExt) {
                          var ext,
                              index = moduleNamePlusExt.lastIndexOf('.'),
                              segment = moduleNamePlusExt.split('/')[0],
                              isRelative = segment === '.' || segment === '..';
  
                          //Have a file extension alias, and it is not the
                          //dots from a relative path.
                          if (index !== -1 && (!isRelative || index > 1)) {
                              ext = moduleNamePlusExt.substring(index, moduleNamePlusExt.length);
                              moduleNamePlusExt = moduleNamePlusExt.substring(0, index);
                          }
  
                          return context.nameToUrl(normalize(moduleNamePlusExt,
                                                  relMap && relMap.id, true), ext,  true);
                      },
  
                      defined: function (id) {
                          return hasProp(defined, makeModuleMap(id, relMap, false, true).id);
                      },
  
                      specified: function (id) {
                          id = makeModuleMap(id, relMap, false, true).id;
                          return hasProp(defined, id) || hasProp(registry, id);
                      }
                  });
  
                  //Only allow undef on top level require calls
                  if (!relMap) {
                      localRequire.undef = function (id) {
                          //Bind any waiting define() calls to this context,
                          //fix for #408
                          takeGlobalQueue();
  
                          var map = makeModuleMap(id, relMap, true),
                              mod = getOwn(registry, id);
  
                          mod.undefed = true;
                          removeScript(id);
  
                          delete defined[id];
                          delete urlFetched[map.url];
                          delete undefEvents[id];
  
                          //Clean queued defines too. Go backwards
                          //in array so that the splices do not
                          //mess up the iteration.
                          eachReverse(defQueue, function(args, i) {
                              if (args[0] === id) {
                                  defQueue.splice(i, 1);
                              }
                          });
                          delete context.defQueueMap[id];
  
                          if (mod) {
                              //Hold on to listeners in case the
                              //module will be attempted to be reloaded
                              //using a different config.
                              if (mod.events.defined) {
                                  undefEvents[id] = mod.events;
                              }
  
                              cleanRegistry(id);
                          }
                      };
                  }
  
                  return localRequire;
              },
  
              /**
               * Called to enable a module if it is still in the registry
               * awaiting enablement. A second arg, parent, the parent module,
               * is passed in for context, when this method is overridden by
               * the optimizer. Not shown here to keep code compact.
               */
              enable: function (depMap) {
                  var mod = getOwn(registry, depMap.id);
                  if (mod) {
                      getModule(depMap).enable();
                  }
              },
  
              /**
               * Internal method used by environment adapters to complete a load event.
               * A load event could be a script load or just a load pass from a synchronous
               * load call.
               * @param {String} moduleName the name of the module to potentially complete.
               */
              completeLoad: function (moduleName) {
                  var found, args, mod,
                      shim = getOwn(config.shim, moduleName) || {},
                      shExports = shim.exports;
  
                  takeGlobalQueue();
  
                  while (defQueue.length) {
                      args = defQueue.shift();
                      if (args[0] === null) {
                          args[0] = moduleName;
                          //If already found an anonymous module and bound it
                          //to this name, then this is some other anon module
                          //waiting for its completeLoad to fire.
                          if (found) {
                              break;
                          }
                          found = true;
                      } else if (args[0] === moduleName) {
                          //Found matching define call for this script!
                          found = true;
                      }
  
                      callGetModule(args);
                  }
                  context.defQueueMap = {};
  
                  //Do this after the cycle of callGetModule in case the result
                  //of those calls/init calls changes the registry.
                  mod = getOwn(registry, moduleName);
  
                  if (!found && !hasProp(defined, moduleName) && mod && !mod.inited) {
                      if (config.enforceDefine && (!shExports || !getGlobal(shExports))) {
                          if (hasPathFallback(moduleName)) {
                              return;
                          } else {
                              return onError(makeError('nodefine',
                                               'No define call for ' + moduleName,
                                               null,
                                               [moduleName]));
                          }
                      } else {
                          //A script that does not call define(), so just simulate
                          //the call for it.
                          callGetModule([moduleName, (shim.deps || []), shim.exportsFn]);
                      }
                  }
  
                  checkLoaded();
              },
  
              /**
               * Converts a module name to a file path. Supports cases where
               * moduleName may actually be just an URL.
               * Note that it **does not** call normalize on the moduleName,
               * it is assumed to have already been normalized. This is an
               * internal API, not a public one. Use toUrl for the public API.
               */
              nameToUrl: function (moduleName, ext, skipExt) {
                  var paths, syms, i, parentModule, url,
                      parentPath, bundleId,
                      pkgMain = getOwn(config.pkgs, moduleName);
  
                  if (pkgMain) {
                      moduleName = pkgMain;
                  }
  
                  bundleId = getOwn(bundlesMap, moduleName);
  
                  if (bundleId) {
                      return context.nameToUrl(bundleId, ext, skipExt);
                  }
  
                  //If a colon is in the URL, it indicates a protocol is used and it is just
                  //an URL to a file, or if it starts with a slash, contains a query arg (i.e. ?)
                  //or ends with .js, then assume the user meant to use an url and not a module id.
                  //The slash is important for protocol-less URLs as well as full paths.
                  if (req.jsExtRegExp.test(moduleName)) {
                      //Just a plain path, not module name lookup, so just return it.
                      //Add extension if it is included. This is a bit wonky, only non-.js things pass
                      //an extension, this method probably needs to be reworked.
                      url = moduleName + (ext || '');
                  } else {
                      //A module that needs to be converted to a path.
                      paths = config.paths;
  
                      syms = moduleName.split('/');
                      //For each module name segment, see if there is a path
                      //registered for it. Start with most specific name
                      //and work up from it.
                      for (i = syms.length; i > 0; i -= 1) {
                          parentModule = syms.slice(0, i).join('/');
  
                          parentPath = getOwn(paths, parentModule);
                          if (parentPath) {
                              //If an array, it means there are a few choices,
                              //Choose the one that is desired
                              if (isArray(parentPath)) {
                                  parentPath = parentPath[0];
                              }
                              syms.splice(0, i, parentPath);
                              break;
                          }
                      }
  
                      //Join the path parts together, then figure out if baseUrl is needed.
                      url = syms.join('/');
                      url += (ext || (/^data\:|\?/.test(url) || skipExt ? '' : '.js'));
                      url = (url.charAt(0) === '/' || url.match(/^[\w\+\.\-]+:/) ? '' : config.baseUrl) + url;
                  }
  
                  return config.urlArgs ? url +
                                          ((url.indexOf('?') === -1 ? '?' : '&') +
                                           config.urlArgs) : url;
              },
  
              //Delegates to req.load. Broken out as a separate function to
              //allow overriding in the optimizer.
              load: function (id, url) {
                  req.load(context, id, url);
              },
  
              /**
               * Executes a module callback function. Broken out as a separate function
               * solely to allow the build system to sequence the files in the built
               * layer in the right sequence.
               *
               * @private
               */
              execCb: function (name, callback, args, exports) {
                  return callback.apply(exports, args);
              },
  
              /**
               * callback for script loads, used to check status of loading.
               *
               * @param {Event} evt the event from the browser for the script
               * that was loaded.
               */
              onScriptLoad: function (evt) {
                  //Using currentTarget instead of target for Firefox 2.0's sake. Not
                  //all old browsers will be supported, but this one was easy enough
                  //to support and still makes sense.
                  if (evt.type === 'load' ||
                          (readyRegExp.test((evt.currentTarget || evt.srcElement).readyState))) {
                      //Reset interactive script so a script node is not held onto for
                      //to long.
                      interactiveScript = null;
  
                      //Pull out the name of the module and the context.
                      var data = getScriptData(evt);
                      context.completeLoad(data.id);
                  }
              },
  
              /**
               * Callback for script errors.
               */
              onScriptError: function (evt) {
                  var data = getScriptData(evt);
                  if (!hasPathFallback(data.id)) {
                      return onError(makeError('scripterror', 'Script error for: ' + data.id, evt, [data.id]));
                  }
              }
          };
  
          context.require = context.makeRequire();
          return context;
      }
  
      /**
       * Main entry point.
       *
       * If the only argument to require is a string, then the module that
       * is represented by that string is fetched for the appropriate context.
       *
       * If the first argument is an array, then it will be treated as an array
       * of dependency string names to fetch. An optional function callback can
       * be specified to execute when all of those dependencies are available.
       *
       * Make a local req variable to help Caja compliance (it assumes things
       * on a require that are not standardized), and to give a short
       * name for minification/local scope use.
       */
      req = requirejs = function (deps, callback, errback, optional) {
  
          //Find the right context, use default
          var context, config,
              contextName = defContextName;
  
          // Determine if have config object in the call.
          if (!isArray(deps) && typeof deps !== 'string') {
              // deps is a config object
              config = deps;
              if (isArray(callback)) {
                  // Adjust args if there are dependencies
                  deps = callback;
                  callback = errback;
                  errback = optional;
              } else {
                  deps = [];
              }
          }
  
          if (config && config.context) {
              contextName = config.context;
          }
  
          context = getOwn(contexts, contextName);
          if (!context) {
              context = contexts[contextName] = req.s.newContext(contextName);
          }
  
          if (config) {
              context.configure(config);
          }
  
          return context.require(deps, callback, errback);
      };
  
      /**
       * Support require.config() to make it easier to cooperate with other
       * AMD loaders on globally agreed names.
       */
      req.config = function (config) {
          return req(config);
      };
  
      /**
       * Execute something after the current tick
       * of the event loop. Override for other envs
       * that have a better solution than setTimeout.
       * @param  {Function} fn function to execute later.
       */
      req.nextTick = typeof setTimeout !== 'undefined' ? function (fn) {
          setTimeout(fn, 4);
      } : function (fn) { fn(); };
  
      /**
       * Export require as a global, but only if it does not already exist.
       */
      if (!require) {
          require = req;
      }
  
      req.version = version;
  
      //Used to filter out dependencies that are already paths.
      req.jsExtRegExp = /^\/|:|\?|\.js$/;
      req.isBrowser = isBrowser;
      s = req.s = {
          contexts: contexts,
          newContext: newContext
      };
  
      //Create default context.
      req({});
  
      //Exports some context-sensitive methods on global require.
      each([
          'toUrl',
          'undef',
          'defined',
          'specified'
      ], function (prop) {
          //Reference from contexts instead of early binding to default context,
          //so that during builds, the latest instance of the default context
          //with its config gets used.
          req[prop] = function () {
              var ctx = contexts[defContextName];
              return ctx.require[prop].apply(ctx, arguments);
          };
      });
  
      if (isBrowser) {
          head = s.head = document.getElementsByTagName('head')[0];
          //If BASE tag is in play, using appendChild is a problem for IE6.
          //When that browser dies, this can be removed. Details in this jQuery bug:
          //http://dev.jquery.com/ticket/2709
          baseElement = document.getElementsByTagName('base')[0];
          if (baseElement) {
              head = s.head = baseElement.parentNode;
          }
      }
  
      /**
       * Any errors that require explicitly generates will be passed to this
       * function. Intercept/override it if you want custom error handling.
       * @param {Error} err the error object.
       */
      req.onError = defaultOnError;
  
      /**
       * Creates the node for the load command. Only used in browser envs.
       */
      req.createNode = function (config, moduleName, url) {
          var node = config.xhtml ?
                  document.createElementNS('http://www.w3.org/1999/xhtml', 'html:script') :
                  document.createElement('script');
          node.type = config.scriptType || 'text/javascript';
          node.charset = 'utf-8';
          node.async = true;
          return node;
      };
  
      /**
       * Does the request to load a module for the browser case.
       * Make this a separate function to allow other environments
       * to override it.
       *
       * @param {Object} context the require context to find state.
       * @param {String} moduleName the name of the module.
       * @param {Object} url the URL to the module.
       */
      req.load = function (context, moduleName, url) {
          var config = (context && context.config) || {},
              node;
          if (isBrowser) {
              //In the browser so use a script tag
              node = req.createNode(config, moduleName, url);
              if (config.onNodeCreated) {
                  config.onNodeCreated(node, config, moduleName, url);
              }
  
              node.setAttribute('data-requirecontext', context.contextName);
              node.setAttribute('data-requiremodule', moduleName);
  
              //Set up load listener. Test attachEvent first because IE9 has
              //a subtle issue in its addEventListener and script onload firings
              //that do not match the behavior of all other browsers with
              //addEventListener support, which fire the onload event for a
              //script right after the script execution. See:
              //https://connect.microsoft.com/IE/feedback/details/648057/script-onload-event-is-not-fired-immediately-after-script-execution
              //UNFORTUNATELY Opera implements attachEvent but does not follow the script
              //script execution mode.
              if (node.attachEvent &&
                      //Check if node.attachEvent is artificially added by custom script or
                      //natively supported by browser
                      //read https://github.com/jrburke/requirejs/issues/187
                      //if we can NOT find [native code] then it must NOT natively supported.
                      //in IE8, node.attachEvent does not have toString()
                      //Note the test for "[native code" with no closing brace, see:
                      //https://github.com/jrburke/requirejs/issues/273
                      !(node.attachEvent.toString && node.attachEvent.toString().indexOf('[native code') < 0) &&
                      !isOpera) {
                  //Probably IE. IE (at least 6-8) do not fire
                  //script onload right after executing the script, so
                  //we cannot tie the anonymous define call to a name.
                  //However, IE reports the script as being in 'interactive'
                  //readyState at the time of the define call.
                  useInteractive = true;
  
                  node.attachEvent('onreadystatechange', context.onScriptLoad);
                  //It would be great to add an error handler here to catch
                  //404s in IE9+. However, onreadystatechange will fire before
                  //the error handler, so that does not help. If addEventListener
                  //is used, then IE will fire error before load, but we cannot
                  //use that pathway given the connect.microsoft.com issue
                  //mentioned above about not doing the 'script execute,
                  //then fire the script load event listener before execute
                  //next script' that other browsers do.
                  //Best hope: IE10 fixes the issues,
                  //and then destroys all installs of IE 6-9.
                  //node.attachEvent('onerror', context.onScriptError);
              } else {
                  node.addEventListener('load', context.onScriptLoad, false);
                  node.addEventListener('error', context.onScriptError, false);
              }
              node.src = url;
  
              //For some cache cases in IE 6-8, the script executes before the end
              //of the appendChild execution, so to tie an anonymous define
              //call to the module name (which is stored on the node), hold on
              //to a reference to this node, but clear after the DOM insertion.
              currentlyAddingScript = node;
              if (baseElement) {
                  head.insertBefore(node, baseElement);
              } else {
                  head.appendChild(node);
              }
              currentlyAddingScript = null;
  
              return node;
          } else if (isWebWorker) {
              try {
                  //In a web worker, use importScripts. This is not a very
                  //efficient use of importScripts, importScripts will block until
                  //its script is downloaded and evaluated. However, if web workers
                  //are in play, the expectation that a build has been done so that
                  //only one script needs to be loaded anyway. This may need to be
                  //reevaluated if other use cases become common.
                  importScripts(url);
  
                  //Account for anonymous modules
                  context.completeLoad(moduleName);
              } catch (e) {
                  context.onError(makeError('importscripts',
                                  'importScripts failed for ' +
                                      moduleName + ' at ' + url,
                                  e,
                                  [moduleName]));
              }
          }
      };
  
      function getInteractiveScript() {
          if (interactiveScript && interactiveScript.readyState === 'interactive') {
              return interactiveScript;
          }
  
          eachReverse(scripts(), function (script) {
              if (script.readyState === 'interactive') {
                  return (interactiveScript = script);
              }
          });
          return interactiveScript;
      }
  
      //Look for a data-main script attribute, which could also adjust the baseUrl.
      if (isBrowser && !cfg.skipDataMain) {
          //Figure out baseUrl. Get it from the script tag with require.js in it.
          eachReverse(scripts(), function (script) {
              //Set the 'head' where we can append children by
              //using the script's parent.
              if (!head) {
                  head = script.parentNode;
              }
  
              //Look for a data-main attribute to set main script for the page
              //to load. If it is there, the path to data main becomes the
              //baseUrl, if it is not already set.
              dataMain = script.getAttribute('data-main');
              if (dataMain) {
                  //Preserve dataMain in case it is a path (i.e. contains '?')
                  mainScript = dataMain;
  
                  //Set final baseUrl if there is not already an explicit one.
                  if (!cfg.baseUrl) {
                      //Pull off the directory of data-main for use as the
                      //baseUrl.
                      src = mainScript.split('/');
                      mainScript = src.pop();
                      subPath = src.length ? src.join('/')  + '/' : './';
  
                      cfg.baseUrl = subPath;
                  }
  
                  //Strip off any trailing .js since mainScript is now
                  //like a module name.
                  mainScript = mainScript.replace(jsSuffixRegExp, '');
  
                  //If mainScript is still a path, fall back to dataMain
                  if (req.jsExtRegExp.test(mainScript)) {
                      mainScript = dataMain;
                  }
  
                  //Put the data-main script in the files to load.
                  cfg.deps = cfg.deps ? cfg.deps.concat(mainScript) : [mainScript];
  
                  return true;
              }
          });
      }
  
      /**
       * The function that handles definitions of modules. Differs from
       * require() in that a string for the module should be the first argument,
       * and the function to execute after dependencies are loaded should
       * return a value to define the module corresponding to the first argument's
       * name.
       */
      define = function (name, deps, callback) {
          var node, context;
  
          //Allow for anonymous modules
          if (typeof name !== 'string') {
              //Adjust args appropriately
              callback = deps;
              deps = name;
              name = null;
          }
  
          //This module may not have dependencies
          if (!isArray(deps)) {
              callback = deps;
              deps = null;
          }
  
          //If no name, and callback is a function, then figure out if it a
          //CommonJS thing with dependencies.
          if (!deps && isFunction(callback)) {
              deps = [];
              //Remove comments from the callback string,
              //look for require calls, and pull them into the dependencies,
              //but only if there are function args.
              if (callback.length) {
                  callback
                      .toString()
                      .replace(commentRegExp, '')
                      .replace(cjsRequireRegExp, function (match, dep) {
                          deps.push(dep);
                      });
  
                  //May be a CommonJS thing even without require calls, but still
                  //could use exports, and module. Avoid doing exports and module
                  //work though if it just needs require.
                  //REQUIRES the function to expect the CommonJS variables in the
                  //order listed below.
                  deps = (callback.length === 1 ? ['require'] : ['require', 'exports', 'module']).concat(deps);
              }
          }
  
          //If in IE 6-8 and hit an anonymous define() call, do the interactive
          //work.
          if (useInteractive) {
              node = currentlyAddingScript || getInteractiveScript();
              if (node) {
                  if (!name) {
                      name = node.getAttribute('data-requiremodule');
                  }
                  context = contexts[node.getAttribute('data-requirecontext')];
              }
          }
  
          //Always save off evaluating the def call until the script onload handler.
          //This allows multiple modules to be in a file without prematurely
          //tracing dependencies, and allows for anonymous module support,
          //where the module name is not known until the script onload event
          //occurs. If no context, use the global queue, and get it processed
          //in the onscript load callback.
          if (context) {
              context.defQueue.push([name, deps, callback]);
              context.defQueueMap[name] = true;
          } else {
              globalDefQueue.push([name, deps, callback]);
          }
      };
  
      define.amd = {
          jQuery: true
      };
  
      /**
       * Executes the text. Normally just uses eval, but can be modified
       * to use a better, environment-specific call. Only used for transpiling
       * loader plugins, not for plain JS modules.
       * @param {String} text the text to execute/evaluate.
       */
      req.exec = function (text) {
          /*jslint evil: true */
          return eval(text);
      };
  
      //Set up with config info.
      req(cfg);
  }(this));
  