@Contract("null -> null")
  private static @Nullable YAMLValue getContainedValue(@Nullable YAMLPsiElement element) {
    if (element == null) {
      return null;
    }
    Ref<YAMLValue> result = Ref.create();
    element.accept(new YamlPsiElementVisitor() {
      @Override
      public void visitKeyValue(@NotNull YAMLKeyValue keyValue) {
        result.set(keyValue.getValue());
      }

      @Override
      public void visitSequenceItem(@NotNull YAMLSequenceItem sequenceItem) {
        result.set(sequenceItem.getValue());
      }
    });
    return result.get();
  }
@Contract("null -> null")
  private static @Nullable YAMLValue getContainedValue(@Nullable YAMLPsiElement element)