code: function forEach(callback, thisArg) {
           var context = this,
               i = 0;
           var len = this.children.length;
  
           if (typeof callback !== "function") {
             throw new Error(callback + " is not a function");
           }
  
           if (arguments.length > 1) {
             context = thisArg;
           }
  
           while (i < len) {
             callback.call(context, this.children[i], i, this.children);
             i++;
           }
         }
docs: The forEach() method executes a provided function once per child element. <br>
  callback is invoked with three arguments: <br>
  - the element value <br>
  - the element index <br>
  - the array being traversed <br>
  @name forEach
  @memberOf me.Container.prototype
  @function
  @param {Function} callback
  @param {Object} [thisArg] value to use as this(i.e reference Object) when executing callback.
  @example
  // iterate through all children of the root container
  me.game.world.forEach(function (child) {
  // do something with the child
  });