@Override
  protected void validateScalarValue(@NotNull YAMLScalar scalarValue, @NotNull ProblemsHolder holder) {
    super.validateScalarValue(scalarValue, holder);

    String text = scalarValue.getTextValue();
    if (text.isEmpty()) {
      // not our business
      return;
    }

    if (Arrays.asList(myDeprecatedLiterals).contains(text)) {
      holder.registerProblem(scalarValue,
                             YAMLBundle.message("YamlEnumType.validation.warning.value.deprecated", text),
                             ProblemHighlightType.LIKE_DEPRECATED);
    }
    else if (Stream.concat(Arrays.stream(myHiddenLiterals), getLiteralsStream()).noneMatch(text::equals)) {
      //TODO quickfix makes sense here if !text.equals(text.toLowerCase)
      holder.registerProblem(scalarValue,
                             YAMLBundle.message("YamlEnumType.validation.error.value.unknown", text),
                             ProblemHighlightType.GENERIC_ERROR_OR_WARNING);
    }
  }
@Override
  protected void validateScalarValue(@NotNull YAMLScalar scalarValue, @NotNull ProblemsHolder holder)