private static void addMergedTabbedContent(@NotNull ContentManager manager,
                                             @NotNull TabGroupId tabGroupId,
                                             @NotNull TabDescriptor tab,
                                             boolean select) {
    TabbedContent tabbedContent = findTabbedContent(manager, tabGroupId.getId());
    if (tabbedContent != null) {
      if (select) {
        manager.setSelectedContent(tabbedContent, true, true);
      }
      tabbedContent.addContent(tab, true);
      return;
    }

    createMergedTabbedContent(manager, tabGroupId, Collections.singletonList(tab), tab, select);
  }
private static void addMergedTabbedContent(@NotNull ContentManager manager,
                                             @NotNull TabGroupId tabGroupId,
                                             @NotNull TabDescriptor tab,
                                             boolean select)