private static @NotNull Language findLanguage(@NotNull PsiFile file) {
      FileViewProvider vp = file.getViewProvider();
      Set<Language> languages = vp.getLanguages();
      for (Language language : languages) {
        if (file.equals(vp.getPsi(language))) {
          return language;
        }
      }
      throw new AssertionError("Non-retrievable file: " + file.getClass() + "; " + file.getLanguage() + "; " + languages);
    }
private static @NotNull Language findLanguage(@NotNull PsiFile file)