code: public static function toStringHelper($identifier) : ToStringHelper
      {
          Preconditions::checkArgument(
              is_object($identifier) || is_string($identifier),
              'An object, a string, or a ReflectionClass must be used as identifier'
          );
          $name = null;
          if ($identifier instanceof ReflectionClass) {
              $name = $identifier->getName();
          } elseif (is_object($identifier)) {
              $name = get_class($identifier);
          } elseif (is_string($identifier)) {
              $name = $identifier;
          }
          return new ToStringHelper($name);
      }
docs: Creates an instance of ToStringHelper.
  This is helpful for implementing ObjectInterface::toString().
  
  @param $identifier
  @throws \InvalidArgumentException
  @return ToStringHelper