@Nullable
  public static ChangeSignatureHandler getChangeSignatureHandler(@NotNull PsiElement language) {
    RefactoringSupportProvider provider = LanguageRefactoringSupport.INSTANCE.forContext(language);
    return provider != null ? provider.getChangeSignatureHandler() : null;
  }
@Nullable
  public static ChangeSignatureHandler getChangeSignatureHandler(@NotNull PsiElement language)