private @Nullable DomExtensionsRegistrarImpl runDomExtenders() {
    DomExtensionsRegistrarImpl registrar = null;
    Project project = myInvocationHandler.getManager().getProject();
    for (DomExtenderEP extenderEP : DomExtenderEP.EP_NAME.getExtensionList()) {
      registrar = extenderEP.extend(project, myInvocationHandler, registrar);
    }

    AbstractDomChildDescriptionImpl description = myInvocationHandler.getChildDescription();
    if (description != null) {
      List<DomExtender<?>> extendersFromParent = description.getUserData(DomExtensionImpl.DOM_EXTENDER_KEY);
      if (extendersFromParent != null) {
        if (registrar == null) registrar = new DomExtensionsRegistrarImpl();
        //noinspection rawtypes
        for (DomExtender extender : extendersFromParent) {
          //noinspection unchecked
          extender.registerExtensions(myInvocationHandler.getProxy(), registrar);
        }
      }
    }
    return registrar;
  }
private @Nullable DomExtensionsRegistrarImpl runDomExtenders()