@Override
  @Contract(pure = true)
  protected @NotNull List<NumberConverter> getConverters(@NotNull PsiFile file) {
    if (!(file instanceof PsiJavaFile)) return Collections.emptyList();
    LanguageLevel level = PsiUtil.getLanguageLevel(file);
    if (level.isLessThan(LanguageLevel.JDK_1_5)) {
      return Holder.JAVA_1_CONVERTERS;
    }
    if (level.isLessThan(LanguageLevel.JDK_1_7)) {
      return Holder.JAVA_5_CONVERTERS;
    }
    return Holder.JAVA_7_CONVERTERS;
  }
@Override
  @Contract(pure = true)
  protected @NotNull List<NumberConverter> getConverters(@NotNull PsiFile file)