text: // "_" service -- underscore.js subset
  // each
  // map
  // reduce
  // reduceRight
  // find
  // filter
  // where
  // findWhere
  // reject
  // all
  // any
  // includes
  // invoke
  // pluck
  // sortBy
  // toArray
  // flatten
  // without
  // indexOf
  // lastIndexOf
  // range
  // findIndex
  // findLastIndex
  // bind
  // keys
  // allKeys
  // values
  // create
  // extend
  // extendOwn
  // pick
  // omit
  // defaults
  // clone
  // has
  // isEqual
  // isEmpty
  // isArray
  // isObject
  // isFunction
  // isString
  // isNumber
  // isBoolean
  // isNaN
  // isNull
  // isUndefined
  
  (function () {
    if (window._) {
      ng._ = window._;
      return;
    }
  
    var _ = ng._ = function () {};
  
    // Save bytes in the minified (but not gzipped) version:
    var ArrayProto = Array.prototype, ObjProto = Object.prototype, FuncProto = Function.prototype;
  
    // Create quick reference variables for speed access to core prototypes.
    var
      push           = ArrayProto.push,
      slice          = ArrayProto.slice,
      toString       = ObjProto.toString,
      hasOwnProperty = ObjProto.hasOwnProperty;
  
    // All **ECMAScript 5** native function implementations that we hope to use
    // are declared here.
    var
      nativeIsArray = Array.isArray,
      nativeKeys    = Object.keys,
      nativeBind    = FuncProto.bind,
      nativeCreate  = Object.create;
  
    // Naked function reference for surrogate-prototype-swapping.
    var Ctor = function () {};
  
    // Internal function that returns an efficient (for current engines) version
    // of the passed-in callback, to be repeatedly applied in other functions.
    var optimizeCb = function(func, context, argCount) {
      if (context === void 0) return func;
      switch (argCount == null ? 3 : argCount) {
        case 1: return function(value) {
          return func.call(context, value);
        };
        case 2: return function(value, other) {
          return func.call(context, value, other);
        };
        case 3: return function(value, index, collection) {
          return func.call(context, value, index, collection);
        };
        case 4: return function(accumulator, value, index, collection) {
          return func.call(context, accumulator, value, index, collection);
        };
      }
      return function() {
        return func.apply(context, arguments);
      };
    };
  
    // A mostly-internal function to generate callbacks that can be applied
    // to each element in a collection, returning the desired result — either
    // identity, an arbitrary callback, a property matcher, or a property accessor.
    var cb = function(value, context, argCount) {
      if (value == null) return _.identity;
      if (_.isFunction(value)) return optimizeCb(value, context, argCount);
      if (_.isObject(value)) return _.matcher(value);
      return _.property(value);
    };
  
    // An internal function for creating assigner functions.
    var createAssigner = function(keysFunc, undefinedOnly) {
      return function(obj) {
        var length = arguments.length;
        if (length < 2 || obj == null) return obj;
        for (var index = 1; index < length; index++) {
          var source = arguments[index],
              keys = keysFunc(source),
              l = keys.length;
          for (var i = 0; i < l; i++) {
            var key = keys[i];
            if (!undefinedOnly || obj[key] === void 0) obj[key] = source[key];
          }
        }
        return obj;
      };
    };
  
    // An internal function for creating a new object that inherits from another.
    var baseCreate = function(prototype) {
      if (!_.isObject(prototype)) return {};
      if (nativeCreate) return nativeCreate(prototype);
      Ctor.prototype = prototype;
      var result = new Ctor;
      Ctor.prototype = null;
      return result;
    };
  
    // Utility Functions
    // -----------------
  
    // Keep the identity function around for default iteratees.
    _.identity = function(value) {
      return value;
    };
  
    _.property = function(key) {
      return function(obj) {
        return obj == null ? void 0 : obj[key];
      };
    };
  
    // Returns a predicate for checking whether an object has a given set of
    // `key:value` pairs.
    _.matcher = _.matches = function(attrs) {
      attrs = _.extendOwn({}, attrs);
      return function(obj) {
        return _.isMatch(obj, attrs);
      };
    };
  
    // Helper for collection methods to determine whether a collection
    // should be iterated as an array or as an object
    // Related: http://people.mozilla.org/~jorendorff/es6-draft.html#sec-tolength
    // Avoids a very nasty iOS 8 JIT bug on ARM-64. #2094
    var MAX_ARRAY_INDEX = Math.pow(2, 53) - 1;
    var getLength = _.property('length');
    var isArrayLike = function(collection) {
      var length = getLength(collection);
      return typeof length == 'number' && length >= 0 && length <= MAX_ARRAY_INDEX;
    };
  
    // Collection Functions
    // --------------------
  
    // The cornerstone, an `each` implementation, aka `forEach`.
    // Handles raw objects in addition to array-likes. Treats all
    // sparse array-likes as if they were dense.
    _.each = _.forEach = function(obj, iteratee, context) {
      iteratee = optimizeCb(iteratee, context);
      var i, length;
      if (isArrayLike(obj)) {
        for (i = 0, length = obj.length; i < length; i++) {
          iteratee(obj[i], i, obj);
        }
      } else {
        var keys = _.keys(obj);
        for (i = 0, length = keys.length; i < length; i++) {
          iteratee(obj[keys[i]], keys[i], obj);
        }
      }
      return obj;
    };
  
    // Return the results of applying the iteratee to each element.
    _.map = _.collect = function(obj, iteratee, context) {
      iteratee = cb(iteratee, context);
      var keys = !isArrayLike(obj) && _.keys(obj),
          length = (keys || obj).length,
          results = Array(length);
      for (var index = 0; index < length; index++) {
        var currentKey = keys ? keys[index] : index;
        results[index] = iteratee(obj[currentKey], currentKey, obj);
      }
      return results;
    };
  
    // Create a reducing function iterating left or right.
    function createReduce(dir) {
      // Optimized iterator function as using arguments.length
      // in the main function will deoptimize the, see #1991.
      function iterator(obj, iteratee, memo, keys, index, length) {
        for (; index >= 0 && index < length; index += dir) {
          var currentKey = keys ? keys[index] : index;
          memo = iteratee(memo, obj[currentKey], currentKey, obj);
        }
        return memo;
      }
  
      return function(obj, iteratee, memo, context) {
        iteratee = optimizeCb(iteratee, context, 4);
        var keys = !isArrayLike(obj) && _.keys(obj),
            length = (keys || obj).length,
            index = dir > 0 ? 0 : length - 1;
        // Determine the initial value if none is provided.
        if (arguments.length < 3) {
          memo = obj[keys ? keys[index] : index];
          index += dir;
        }
        return iterator(obj, iteratee, memo, keys, index, length);
      };
    }
  
    // **Reduce** builds up a single result from a list of values, aka `inject`,
    // or `foldl`.
    _.reduce = _.foldl = _.inject = createReduce(1);
  
    // The right-associative version of reduce, also known as `foldr`.
    _.reduceRight = _.foldr = createReduce(-1);
  
    // Return the first value which passes a truth test. Aliased as `detect`.
    _.find = _.detect = function(obj, predicate, context) {
      var key;
      if (isArrayLike(obj)) {
        key = _.findIndex(obj, predicate, context);
      } else {
        key = _.findKey(obj, predicate, context);
      }
      if (key !== void 0 && key !== -1) return obj[key];
    };
  
    // Return all the elements that pass a truth test.
    // Aliased as `select`.
    _.filter = _.select = function(obj, predicate, context) {
      var results = [];
      predicate = cb(predicate, context);
      _.each(obj, function(value, index, list) {
        if (predicate(value, index, list)) results.push(value);
      });
      return results;
    };
  
    // Return all the elements for which a truth test fails.
    _.reject = function(obj, predicate, context) {
      return _.filter(obj, _.negate(cb(predicate)), context);
    };
  
    // Determine whether all of the elements match a truth test.
    // Aliased as `all`.
    _.every = _.all = function(obj, predicate, context) {
      predicate = cb(predicate, context);
      var keys = !isArrayLike(obj) && _.keys(obj),
          length = (keys || obj).length;
      for (var index = 0; index < length; index++) {
        var currentKey = keys ? keys[index] : index;
        if (!predicate(obj[currentKey], currentKey, obj)) return false;
      }
      return true;
    };
  
    // Determine if at least one element in the object matches a truth test.
    // Aliased as `any`.
    _.some = _.any = function(obj, predicate, context) {
      predicate = cb(predicate, context);
      var keys = !isArrayLike(obj) && _.keys(obj),
          length = (keys || obj).length;
      for (var index = 0; index < length; index++) {
        var currentKey = keys ? keys[index] : index;
        if (predicate(obj[currentKey], currentKey, obj)) return true;
      }
      return false;
    };
  
    // Determine if the array or object contains a given item (using `===`).
    // Aliased as `includes` and `include`.
    _.contains = _.includes = _.include = function(obj, item, fromIndex, guard) {
      if (!isArrayLike(obj)) obj = _.values(obj);
      if (typeof fromIndex != 'number' || guard) fromIndex = 0;
      return _.indexOf(obj, item, fromIndex) >= 0;
    };
  
    // Invoke a method (with arguments) on every item in a collection.
    _.invoke = function(obj, method) {
      var args = slice.call(arguments, 2);
      var isFunc = _.isFunction(method);
      return _.map(obj, function(value) {
        var func = isFunc ? method : value[method];
        return func == null ? func : func.apply(value, args);
      });
    };
  
    // Convenience version of a common use case of `map`: fetching a property.
    _.pluck = function(obj, key) {
      return _.map(obj, _.property(key));
    };
  
    // Convenience version of a common use case of `filter`: selecting only objects
    // containing specific `key:value` pairs.
    _.where = function(obj, attrs) {
      return _.filter(obj, _.matcher(attrs));
    };
  
    // Convenience version of a common use case of `find`: getting the first object
    // containing specific `key:value` pairs.
    _.findWhere = function(obj, attrs) {
      return _.find(obj, _.matcher(attrs));
    };
  
    // Sort the object's values by a criterion produced by an iteratee.
    _.sortBy = function(obj, iteratee, context) {
      iteratee = cb(iteratee, context);
      return _.pluck(_.map(obj, function(value, index, list) {
        return {
          value: value,
          index: index,
          criteria: iteratee(value, index, list)
        };
      }).sort(function(left, right) {
        var a = left.criteria;
        var b = right.criteria;
        if (a !== b) {
          if (a > b || a === void 0) return 1;
          if (a < b || b === void 0) return -1;
        }
        return left.index - right.index;
      }), 'value');
    };
  
    // Safely create a real, live array from anything iterable.
    _.toArray = function(obj) {
      if (!obj) return [];
      if (_.isArray(obj)) return slice.call(obj);
      if (isArrayLike(obj)) return _.map(obj, _.identity);
      return _.values(obj);
    };
  
    // Array Functions
    // ---------------
  
    // Internal implementation of a recursive `flatten` function.
    var flatten = function(input, shallow, strict, startIndex) {
      var output = [], idx = 0;
      for (var i = startIndex || 0, length = getLength(input); i < length; i++) {
        var value = input[i];
        if (isArrayLike(value) && (_.isArray(value) || _.isArguments(value))) {
          //flatten current level of array or arguments object
          if (!shallow) value = flatten(value, shallow, strict);
          var j = 0, len = value.length;
          output.length += len;
          while (j < len) {
            output[idx++] = value[j++];
          }
        } else if (!strict) {
          output[idx++] = value;
        }
      }
      return output;
    };
  
    // Flatten out an array, either recursively (by default), or just one level.
    _.flatten = function(array, shallow) {
      return flatten(array, shallow, false);
    };
  
    // Return a version of the array that does not contain the specified value(s).
    _.without = function(array) {
      return _.difference(array, slice.call(arguments, 1));
    };
  
    // Take the difference between one array and a number of other arrays.
    // Only the elements present in just the first array will remain.
    _.difference = function(array) {
      var rest = flatten(arguments, true, true, 1);
      return _.filter(array, function(value){
        return !_.contains(rest, value);
      });
    };
  
    // Generator function to create the findIndex and findLastIndex functions
    function createPredicateIndexFinder(dir) {
      return function(array, predicate, context) {
        predicate = cb(predicate, context);
        var length = getLength(array);
        var index = dir > 0 ? 0 : length - 1;
        for (; index >= 0 && index < length; index += dir) {
          if (predicate(array[index], index, array)) return index;
        }
        return -1;
      };
    }
  
    // Returns the first index on an array-like that passes a predicate test
    _.findIndex = createPredicateIndexFinder(1);
    _.findLastIndex = createPredicateIndexFinder(-1);
  
    // Use a comparator function to figure out the smallest index at which
    // an object should be inserted so as to maintain order. Uses binary search.
    _.sortedIndex = function(array, obj, iteratee, context) {
      iteratee = cb(iteratee, context, 1);
      var value = iteratee(obj);
      var low = 0, high = getLength(array);
      while (low < high) {
        var mid = Math.floor((low + high) / 2);
        if (iteratee(array[mid]) < value) low = mid + 1; else high = mid;
      }
      return low;
    };
  
    // Generator function to create the indexOf and lastIndexOf functions
    function createIndexFinder(dir, predicateFind, sortedIndex) {
      return function(array, item, idx) {
        var i = 0, length = getLength(array);
        if (typeof idx == 'number') {
          if (dir > 0) {
              i = idx >= 0 ? idx : Math.max(idx + length, i);
          } else {
              length = idx >= 0 ? Math.min(idx + 1, length) : idx + length + 1;
          }
        } else if (sortedIndex && idx && length) {
          idx = sortedIndex(array, item);
          return array[idx] === item ? idx : -1;
        }
        if (item !== item) {
          idx = predicateFind(slice.call(array, i, length), _.isNaN);
          return idx >= 0 ? idx + i : -1;
        }
        for (idx = dir > 0 ? i : length - 1; idx >= 0 && idx < length; idx += dir) {
          if (array[idx] === item) return idx;
        }
        return -1;
      };
    }
  
    // Return the position of the first occurrence of an item in an array,
    // or -1 if the item is not included in the array.
    // If the array is large and already in sort order, pass `true`
    // for **isSorted** to use binary search.
    _.indexOf = createIndexFinder(1, _.findIndex, _.sortedIndex);
    _.lastIndexOf = createIndexFinder(-1, _.findLastIndex);
  
    // Generate an integer Array containing an arithmetic progression. A port of
    // the native Python `range()` function. See
    // [the Python documentation](http://docs.python.org/library/functions.html#range).
    _.range = function(start, stop, step) {
      if (stop == null) {
        stop = start || 0;
        start = 0;
      }
      step = step || 1;
  
      var length = Math.max(Math.ceil((stop - start) / step), 0);
      var range = Array(length);
  
      for (var idx = 0; idx < length; idx++, start += step) {
        range[idx] = start;
      }
  
      return range;
    };
  
    // Function (ahem) Functions
    // ------------------
  
    // Determines whether to execute a function as a constructor
    // or a normal function with the provided arguments
    var executeBound = function(sourceFunc, boundFunc, context, callingContext, args) {
      if (!(callingContext instanceof boundFunc)) return sourceFunc.apply(context, args);
      var self = baseCreate(sourceFunc.prototype);
      var result = sourceFunc.apply(self, args);
      if (_.isObject(result)) return result;
      return self;
    };
  
    // Create a function bound to a given object (assigning `this`, and arguments,
    // optionally). Delegates to **ECMAScript 5**'s native `Function.bind` if
    // available.
    _.bind = function(func, context) {
      if (nativeBind && func.bind === nativeBind) return nativeBind.apply(func, slice.call(arguments, 1));
      if (!_.isFunction(func)) throw new TypeError('Bind must be called on a function');
      var args = slice.call(arguments, 2);
      var bound = function() {
        return executeBound(func, bound, context, this, args.concat(slice.call(arguments)));
      };
      return bound;
    };
  
    // Returns a negated version of the passed-in predicate.
    _.negate = function(predicate) {
      return function() {
        return !predicate.apply(this, arguments);
      };
    };
  
    // Object Functions
    // ----------------
  
    // Keys in IE < 9 that won't be iterated by `for key in ...` and thus missed.
    var hasEnumBug = !{toString: null}.propertyIsEnumerable('toString');
    var nonEnumerableProps = ['valueOf', 'isPrototypeOf', 'toString',
                        'propertyIsEnumerable', 'hasOwnProperty', 'toLocaleString'];
  
    function collectNonEnumProps(obj, keys) {
      var nonEnumIdx = nonEnumerableProps.length;
      var constructor = obj.constructor;
      var proto = (_.isFunction(constructor) && constructor.prototype) || ObjProto;
  
      // Constructor is a special case.
      var prop = 'constructor';
      if (_.has(obj, prop) && !_.contains(keys, prop)) keys.push(prop);
  
      while (nonEnumIdx--) {
        prop = nonEnumerableProps[nonEnumIdx];
        if (prop in obj && obj[prop] !== proto[prop] && !_.contains(keys, prop)) {
          keys.push(prop);
        }
      }
    }
  
    // Retrieve the names of an object's own properties.
    // Delegates to **ECMAScript 5**'s native `Object.keys`
    _.keys = function(obj) {
      if (!_.isObject(obj)) return [];
      if (nativeKeys) return nativeKeys(obj);
      var keys = [];
      for (var key in obj) if (_.has(obj, key)) keys.push(key);
      // Ahem, IE < 9.
      if (hasEnumBug) collectNonEnumProps(obj, keys);
      return keys;
    };
  
    // Retrieve all the property names of an object.
    _.allKeys = function(obj) {
      if (!_.isObject(obj)) return [];
      var keys = [];
      for (var key in obj) keys.push(key);
      // Ahem, IE < 9.
      if (hasEnumBug) collectNonEnumProps(obj, keys);
      return keys;
    };
  
    // Retrieve the values of an object's properties.
    _.values = function(obj) {
      var keys = _.keys(obj);
      var length = keys.length;
      var values = Array(length);
      for (var i = 0; i < length; i++) {
        values[i] = obj[keys[i]];
      }
      return values;
    };
  
    // Extend a given object with all the properties in passed-in object(s).
    _.extend = createAssigner(_.allKeys);
  
    // Assigns a given object with all the own properties in the passed-in object(s)
    // (https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object/assign)
    _.extendOwn = _.assign = createAssigner(_.keys);
  
    // Return a copy of the object only containing the whitelisted properties.
    _.pick = function(object, oiteratee, context) {
      var result = {}, obj = object, iteratee, keys;
      if (obj == null) return result;
      if (_.isFunction(oiteratee)) {
        keys = _.allKeys(obj);
        iteratee = optimizeCb(oiteratee, context);
      } else {
        keys = flatten(arguments, false, false, 1);
        iteratee = function(value, key, obj) { return key in obj; };
        obj = Object(obj);
      }
      for (var i = 0, length = keys.length; i < length; i++) {
        var key = keys[i];
        var value = obj[key];
        if (iteratee(value, key, obj)) result[key] = value;
      }
      return result;
    };
  
     // Return a copy of the object without the blacklisted properties.
    _.omit = function(obj, iteratee, context) {
      if (_.isFunction(iteratee)) {
        iteratee = _.negate(iteratee);
      } else {
        var keys = _.map(flatten(arguments, false, false, 1), String);
        iteratee = function(value, key) {
          return !_.contains(keys, key);
        };
      }
      return _.pick(obj, iteratee, context);
    };
  
    // Fill in a given object with default properties.
    _.defaults = createAssigner(_.allKeys, true);
  
    // Creates an object that inherits from the given prototype object.
    // If additional properties are provided then they will be added to the
    // created object.
    _.create = function(prototype, props) {
      var result = baseCreate(prototype);
      if (props) _.extendOwn(result, props);
      return result;
    };
  
    // Create a (shallow-cloned) duplicate of an object.
    _.clone = function(obj) {
      if (!_.isObject(obj)) return obj;
      return _.isArray(obj) ? obj.slice() : _.extend({}, obj);
    };
  
    // Returns whether an object has a given set of `key:value` pairs.
    _.isMatch = function(object, attrs) {
      var keys = _.keys(attrs), length = keys.length;
      if (object == null) return !length;
      var obj = Object(object);
      for (var i = 0; i < length; i++) {
        var key = keys[i];
        if (attrs[key] !== obj[key] || !(key in obj)) return false;
      }
      return true;
    };
  
    // Internal recursive comparison function for `isEqual`.
    var eq = function(a, b, aStack, bStack) {
      // Identical objects are equal. `0 === -0`, but they aren't identical.
      // See the [Harmony `egal` proposal](http://wiki.ecmascript.org/doku.php?id=harmony:egal).
      if (a === b) return a !== 0 || 1 / a === 1 / b;
      // A strict comparison is necessary because `null == undefined`.
      if (a == null || b == null) return a === b;
      // Unwrap any wrapped objects.
      if (a instanceof _) a = a._wrapped;
      if (b instanceof _) b = b._wrapped;
      // Compare `[[Class]]` names.
      var className = toString.call(a);
      if (className !== toString.call(b)) return false;
      switch (className) {
        // Strings, numbers, regular expressions, dates, and booleans are compared by value.
        case '[object RegExp]':
        // RegExps are coerced to strings for comparison (Note: '' + /a/i === '/a/i')
        case '[object String]':
          // Primitives and their corresponding object wrappers are equivalent; thus, `"5"` is
          // equivalent to `new String("5")`.
          return '' + a === '' + b;
        case '[object Number]':
          // `NaN`s are equivalent, but non-reflexive.
          // Object(NaN) is equivalent to NaN
          if (+a !== +a) return +b !== +b;
          // An `egal` comparison is performed for other numeric values.
          return +a === 0 ? 1 / +a === 1 / b : +a === +b;
        case '[object Date]':
        case '[object Boolean]':
          // Coerce dates and booleans to numeric primitive values. Dates are compared by their
          // millisecond representations. Note that invalid dates with millisecond representations
          // of `NaN` are not equivalent.
          return +a === +b;
      }
  
      var areArrays = className === '[object Array]';
      if (!areArrays) {
        if (typeof a != 'object' || typeof b != 'object') return false;
  
        // Objects with different constructors are not equivalent, but `Object`s or `Array`s
        // from different frames are.
        var aCtor = a.constructor, bCtor = b.constructor;
        if (aCtor !== bCtor && !(_.isFunction(aCtor) && aCtor instanceof aCtor &&
                                 _.isFunction(bCtor) && bCtor instanceof bCtor)
                            && ('constructor' in a && 'constructor' in b)) {
          return false;
        }
      }
      // Assume equality for cyclic structures. The algorithm for detecting cyclic
      // structures is adapted from ES 5.1 section 15.12.3, abstract operation `JO`.
  
      // Initializing stack of traversed objects.
      // It's done here since we only need them for objects and arrays comparison.
      aStack = aStack || [];
      bStack = bStack || [];
      var length = aStack.length;
      while (length--) {
        // Linear search. Performance is inversely proportional to the number of
        // unique nested structures.
        if (aStack[length] === a) return bStack[length] === b;
      }
  
      // Add the first object to the stack of traversed objects.
      aStack.push(a);
      bStack.push(b);
  
      // Recursively compare objects and arrays.
      if (areArrays) {
        // Compare array lengths to determine if a deep comparison is necessary.
        length = a.length;
        if (length !== b.length) return false;
        // Deep compare the contents, ignoring non-numeric properties.
        while (length--) {
          if (!eq(a[length], b[length], aStack, bStack)) return false;
        }
      } else {
        // Deep compare objects.
        var keys = _.keys(a), key;
        length = keys.length;
        // Ensure that both objects contain the same number of properties before comparing deep equality.
        if (_.keys(b).length !== length) return false;
        while (length--) {
          // Deep compare each member
          key = keys[length];
          if (!(_.has(b, key) && eq(a[key], b[key], aStack, bStack))) return false;
        }
      }
      // Remove the first object from the stack of traversed objects.
      aStack.pop();
      bStack.pop();
      return true;
    };
  
    // Perform a deep comparison to check if two objects are equal.
    _.isEqual = function(a, b) {
      return eq(a, b);
    };
  
    // Is a given array, string, or object empty?
    // An "empty" object has no enumerable own-properties.
    _.isEmpty = function(obj) {
      if (obj == null) return true;
      if (isArrayLike(obj) && (_.isArray(obj) || _.isString(obj) || _.isArguments(obj))) return obj.length === 0;
      return _.keys(obj).length === 0;
    };
  
    // Is a given value an array?
    // Delegates to ECMA5's native Array.isArray
    _.isArray = nativeIsArray || function(obj) {
      return toString.call(obj) === '[object Array]';
    };
  
    // Is a given variable an object?
    _.isObject = function(obj) {
      var type = typeof obj;
      return type === 'function' || type === 'object' && !!obj;
    };
  
    // Add some isType methods: isArguments, isFunction, isString, isNumber, isDate, isRegExp, isError.
    _.each(['Arguments', 'Function', 'String', 'Number', 'Date', 'RegExp', 'Error'], function(name) {
      _['is' + name] = function(obj) {
        return toString.call(obj) === '[object ' + name + ']';
      };
    });
  
    // Define a fallback version of the method in browsers (ahem, IE < 9), where
    // there isn't any inspectable "Arguments" type.
    if (!_.isArguments(arguments)) {
      _.isArguments = function(obj) {
        return _.has(obj, 'callee');
      };
    }
  
    // Optimize `isFunction` if appropriate. Work around some typeof bugs in old v8,
    // IE 11 (#1621), and in Safari 8 (#1929).
    if (typeof /./ != 'function' && typeof Int8Array != 'object') {
      _.isFunction = function(obj) {
        return typeof obj == 'function' || false;
      };
    }
  
    // Is the given value `NaN`? (NaN is the only number which does not equal itself).
    _.isNaN = function(obj) {
      return _.isNumber(obj) && obj !== +obj;
    };
  
    // Is a given value a boolean?
    _.isBoolean = function(obj) {
      return obj === true || obj === false || toString.call(obj) === '[object Boolean]';
    };
  
    // Is a given value equal to null?
    _.isNull = function(obj) {
      return obj === null;
    };
  
    // Is a given variable undefined?
    _.isUndefined = function(obj) {
      return obj === void 0;
    };
  
    // Shortcut function for checking if an object has a given property directly
    // on itself (in other words, not on a prototype).
    _.has = function(obj, key) {
      return obj != null && hasOwnProperty.call(obj, key);
    };
  })();
  
  (function (_) {
    ng.value('_', [], _);
  })(ng._);
  
  ng._ = null;
  
  