text: /* */ 
  System.register([], function (_export) {
    "use strict";
  
    var _prototypeProperties, Headers;
    return {
      setters: [],
      execute: function () {
        _prototypeProperties = function (child, staticProps, instanceProps) {
          if (staticProps) Object.defineProperties(child, staticProps);
          if (instanceProps) Object.defineProperties(child.prototype, instanceProps);
        };
  
        Headers = (function () {
          function Headers() {
            var headers = arguments[0] === undefined ? {} : arguments[0];
            this.headers = headers;
          }
  
          _prototypeProperties(Headers, null, {
            add: {
              value: function add(key, value) {
                this.headers[key] = value;
              },
              writable: true,
              enumerable: true,
              configurable: true
            },
            get: {
              value: function get(key) {
                return this.headers[key];
              },
              writable: true,
              enumerable: true,
              configurable: true
            },
            clear: {
              value: function clear() {
                this.headers = {};
              },
              writable: true,
              enumerable: true,
              configurable: true
            },
            configureXHR: {
              value: function configureXHR(xhr) {
                var headers = this.headers,
                    key;
  
                for (key in headers) {
                  xhr.setRequestHeader(key, headers[key]);
                }
              },
              writable: true,
              enumerable: true,
              configurable: true
            }
          });
  
          return Headers;
        })();
        _export("Headers", Headers);
      }
    };
  });