code: public static function isValidLiteralValue(Type $type, $valueNode)
      {
          $emptySchema = new Schema([]);
          $emptyDoc    = new DocumentNode(['definitions' => []]);
          $typeInfo    = new TypeInfo($emptySchema, $type);
          $context     = new ValidationContext($emptySchema, $emptyDoc, $typeInfo);
          $validator   = new ValuesOfCorrectType();
          $visitor     = $validator->getVisitor($context);
          Visitor::visit($valueNode, Visitor::visitWithTypeInfo($typeInfo, $visitor));
  
          return $context->getErrors();
      }
docs: Utility which determines if a value literal node is valid for an input type.
  
  Deprecated. Rely on validation for documents co
  ntaining literal values.
  
  @deprecated
  
  @return Error[]