code: public function setTranslator(TranslatorInterface $translator = null, $textDomain = null)
      {
          if ($translator) {
              $this->translator = $translator;
          }
          $this->setTranslatorTextDomain($textDomain);
          return $this;
      }
docs: /* (non-PHPdoc)
  @see \Zend\I18n\Translator\TranslatorAwareInterface::setTranslator()