text: define([], function () {
    'use strict';
  
    function ChatUIMock() {
      ChatUIMock.instance = this;
      this._constructor.apply(this, arguments);
    }
    ChatUIMock.prototype._constructor = sinon.spy();
    ChatUIMock.prototype.enableSending = function () {};
    ChatUIMock.prototype.disableSending = function () {};
    ChatUIMock.prototype.fakeClickOnSend = function (contents, callback) {
      this.onMessageReadyToSend(contents, callback);
    };
    ChatUIMock.prototype.addMessage = sinon.spy();
  
    return ChatUIMock;
  });
  