code: function() {
              if(Kinetic.Node.prototype.moveDown.call(this)) {
                  var stage = this.getStage();
                  if(stage) {
                      var children = stage.getChildren();
                      stage.content.removeChild(this.getCanvas()._canvas);
                      stage.content.insertBefore(this.getCanvas()._canvas, children[this.index + 1].getCanvas()._canvas);
                  }
              }
          }
docs: extend Node.prototype.moveDown