/**
  * @param IdentityInterface $identity
  *
  * @return string
  */
 private function assembleIdKey(IdentityInterface $identity)
 {
     $idKey = IdentityUtils::assembleKey($identity);
     return $idKey;
 }
 /**
  * @inheritdoc
  */
 public function contains(IdentityAwareGetterInterface $object)
 {
     $key = IdentityUtils::assembleKey($object->getIdentity());
     return array_key_exists($key, $this->objects);
 }