@Override
  public void validateValue(@NotNull YAMLValue value, @NotNull ProblemsHolder problemsHolder) {
    super.validateValue(value, problemsHolder);
    if (value instanceof YAMLScalar && !YamlMetaUtil.isNull(value)) {
      problemsHolder.registerProblem(value,
                                     YAMLBundle.message("YamlMetaClass.error.scalar.value", ArrayUtil.EMPTY_OBJECT_ARRAY));
    }
  }
@Override
  public void validateValue(@NotNull YAMLValue value, @NotNull ProblemsHolder problemsHolder)