code: function() {
          var i = 0,
              arg = arguments,
              l = arguments.length,
              obj;
          for (; i < l; ++i) {
              obj = arg[i];
              if (obj._parent) {
                  obj._parent.detach(obj);
              }
              obj._parent = this;
              this._children.push(obj);
          }
  
          return this;
      }
docs: @
  #.attach
  @comp 2D
  @kind Method
  
  @sign public this .attach(Entity obj[, .., Entity objN])
  @param obj - Child entity(s) to attach
  
  Sets one or more entities to be children, with the current entity (`this`)
  as the parent. When the parent moves or rotates, its children move or
  rotate by the same amount. (But not vice-versa: If you move a child, it
  will not move the parent.) When the parent is destroyed, its children are
  destroyed.
  
  For any entity, `this._children` is the array of its children entity
  objects (if any), and `this._parent` is its parent entity object (if any).
  
  As many objects as wanted can be attached, and a hierarchy of objects is
  possible by attaching.