code: function cleanupDropdown() {
          $("html").off("click", closeDropdown);
          $("#project-files-container").off("scroll", closeDropdown);
          $("#titlebar .nav").off("click", closeDropdown);
          $dropdown = null;
  
          MainViewManager.focusActivePane();
  
          $(window).off("keydown", keydownHook);
      }
docs: Remove the various event handlers that close the dropdown. This is called by the
  PopUpManager when the dropdown is closed.