code: function getPanelByPoint(controller, e, localCursorPoint) {
      var panels = controller._panels;
      if (!panels) {
          return true; // Global panel
      }
      var panel;
      var transform = controller._transform;
      each(panels, function (pn) {
          pn.isTargetByCursor(e, localCursorPoint, transform) && (panel = pn);
      });
      return panel;
  }
docs: return target panel or `true` (means global panel)