protected @Nullable PsiFile createFile(@NotNull Language lang) {
    if (lang != getBaseLanguage()) return null;
    ParserDefinition parserDefinition = LanguageParserDefinitions.INSTANCE.forLanguage(lang);
    if (parserDefinition != null) {
      return parserDefinition.createFile(this);
    }
    return null;
  }
protected @Nullable PsiFile createFile(@NotNull Language lang)