public static boolean fileContainsXmlLanguage(@Nullable PsiFile editedFile) {
    if (editedFile == null) return false;
    if (editedFile.getLanguage() instanceof XMLLanguage) {
      return true;
    }
    if (HtmlUtil.supportsXmlTypedHandlers(editedFile)) {
      return true;
    }
    final FileViewProvider provider = editedFile.getViewProvider();
    if (provider.getBaseLanguage() instanceof XMLLanguage) {
      return true;
    }
    return provider instanceof TemplateLanguageFileViewProvider &&
           ((TemplateLanguageFileViewProvider)provider).getTemplateDataLanguage() instanceof XMLLanguage;
  }
public static boolean fileContainsXmlLanguage(@Nullable PsiFile editedFile)