code: function(view, rowElement, groupName, e) {
          var me = this,
              groupCache = me.groupCache,
              groupIsCollapsed = !me.isExpanded(groupName),
              g;
  
          if (me.collapsible) {
  
              // CTRL means collapse all others
              if (e.ctrlKey) {
                  Ext.suspendLayouts();
                  for (g in groupCache) {
                      if (g === groupName) {
                          if (groupIsCollapsed) {
                              me.expand(groupName);
                          }
                      } else {
                          me.doCollapseExpand(true, g, false);
                      }
                  }
                  Ext.resumeLayouts(true);
                  return;
              }
  
              if (groupIsCollapsed) {
                 me.expand(groupName);
              } else {
                  me.collapse(groupName);
              }
          }
      }
docs: Toggle between expanded/collapsed state when clicking on
  the group.
  @private