private @NotNull DefaultActionGroup getCommonActionGroup() {
      DefaultActionGroup commonActionGroup = new DefaultActionGroup();
      for (int i = 0; i < myGroups.size(); i++) {
        ActionGroup popupActions = myGroups.get(i);
        if (popupActions != null) {
          commonActionGroup.addSeparator();
          commonActionGroup.addAll(popupActions);
        }
        else {
          MergeableLineMarkerInfo<?> mergeableLineMarkerInfo = myMarkers.get(i);
          commonActionGroup.add(mergeableLineMarkerInfo.getNavigateAction());
        }
      }
      return commonActionGroup;
    }
private @NotNull DefaultActionGroup getCommonActionGroup()