@Nullable
  private Module getSelectedModule() {
    final Object selected = getModuleStructureConfigurable().getSelectedObject();
    if (selected instanceof Module) {
      return (Module)selected;
    }
    if (selected instanceof Facet) {
      return ((Facet<?>)selected).getModule();
    }
    return null;
  }
@Nullable
  private Module getSelectedModule()