private static void registerContributedReferenceProviders(@NotNull PsiReferenceRegistrarImpl registrar,
                                                            @NotNull PsiReferenceContributor contributor) {
    contributor.registerReferenceProviders(registrar);
  }
private static void registerContributedReferenceProviders(@NotNull PsiReferenceRegistrarImpl registrar,
                                                            @NotNull PsiReferenceContributor contributor)