code: function () {
              if (!this.visible) {
                  // add the debug panel to the game world
                  me.game.world.addChild(this, Infinity);
                  // register a mouse event for the checkboxes
                  me.input.registerPointerEvent("pointerdown", this, this.onClick.bind(this));
                  // mark it as visible
                  this.visible = true;
                  // force repaint
                  me.game.repaint();
              }
          }
docs: show the debug panel
  @ignore