code: public function getHydrator($namespace)
      {
          $namespaceOptions = $this->options->getNamespaceOptions($namespace);
          $hydrator = $namespaceOptions->getHydrator();
          if ($hydrator instanceof HydratorInterface) {
              return $hydrator;
          }
          if (is_string($hydrator)) {
              if ($this->hydrators->has($hydrator)) {
                  return $this->hydrators->get($hydrator);
              }
              if (class_exists($hydrator)) {
                  $hydratorObject = new $hydrator;
                  if ($hydratorObject instanceof HydratorInterface) {
                      return $hydratorObject;
                  }
              }
          }
  
          throw new Exception\RuntimeException(sprintf(
              'Hydrator of settings namespace, %s is neither a service or class name or instanceof Zend\Stdlib\Hydrator\HydratorInterface; %s provided instead',
              $namespace,
              is_object($hydrator) ? get_class($hydrator) : gettype($hydrator)
          ));
      }
docs: {@inheritDoc}