code: public function guard($value, Field $field)
      {
          /** @var Message $value */
          Assertion::isInstanceOf($value, Message::class, null, $field->getName());
  
          $classNames = $field->getAnyOfClassNames();
          if (empty($classNames)) {
              // means it can be "any message"
              return;
          }
  
          foreach ($classNames as $className) {
              if ($value instanceof $className) {
                  return;
              }
          }
  
          Assertion::true(
              false,
              sprintf(
                  'Field [%s] must be an instance of at least one of: %s.',
                  $field->getName(),
                  implode(',', $classNames)
              ),
              $field->getName()
          );
      }
docs: {@inheritdoc}