code: function _showPanelsIfRequired() {
          var panelIDs = _previouslyOpenPanelIDs;
          panelIDs.forEach(function (panelID) {
              var panel = WorkspaceManager.getPanelForID(panelID);
              if (panel) {
                  panel.show();
              }
          });
          _previouslyOpenPanelIDs = [];
      }
docs: show all open panels that was previously hidden by _hidePanelsIfRequired()