code: function( x, y ) {
  		if( !this.header._canDestroy )
  			return null;
  		if( this.contentItem.parent.isMaximised === true ) {
  			this.contentItem.parent.toggleMaximise();
  		}
  		new lm.controls.DragProxy(
  			x,
  			y,
  			this._dragListener,
  			this._layoutManager,
  			this.contentItem,
  			this.header.parent
  		);
  	}
docs: Callback for the DragListener
  
  @param   {Number} x The tabs absolute x position
  @param   {Number} y The tabs absolute y position
  
  @private
  @returns {void}