@TestOnly
  public static void setRootArea(@NotNull ExtensionsAreaImpl area, @NotNull Disposable parentDisposable) {
    ExtensionsAreaImpl oldRootArea = rootArea;
    rootArea = area;
    Disposer.register(parentDisposable, () -> {
      rootArea.notifyAreaReplaced(oldRootArea);
      rootArea = oldRootArea;
    });
  }
@TestOnly
  public static void setRootArea(@NotNull ExtensionsAreaImpl area, @NotNull Disposable parentDisposable)