static @Nullable LanguageItem fromLanguage(@NotNull Language language) {
      LanguageFileType fileType = language.getAssociatedFileType();
      String defaultExtension = fileType == null ? null : fileType.getDefaultExtension();
      if (StringUtil.isEmpty(defaultExtension)) return null;
      return new LanguageItem(language, fileType, defaultExtension);
    }
static @Nullable LanguageItem fromLanguage(@NotNull Language language)