Doctrine\ORM\UnitOfWork::isInIdentityMap PHP Method

    public function isInIdentityMap($entity)
    {
        $oid = spl_object_hash($entity);
        if ( ! isset($this->entityIdentifiers[$oid])) {
            return false;
        }
        $classMetadata = $this->em->getClassMetadata(get_class($entity));
        $idHash = implode(' ', $this->entityIdentifiers[$oid]);
        if ($idHash === '') {
            return false;
        }
        
        return isset($this->identityMap[$classMetadata->rootEntityName][$idHash]);
    }

 /**
  * {@inheritdoc}
  */
 public function buildCacheEntry(ClassMetadata $metadata, EntityCacheKey $key, $entity)
 {
     $data = $this->uow->getOriginalEntityData($entity);
     $data = array_merge($data, $key->identifier);
     // why update has no identifier values ?
     foreach ($metadata->associationMappings as $name => $assoc) {
         if (!isset($data[$name])) {
             continue;
         }
         if (!isset($assoc['cache']) || !($assoc['type'] & ClassMetadata::TO_ONE)) {
             unset($data[$name]);
             continue;
         }
         if (!isset($assoc['id'])) {
             $targetClass = ClassUtils::getClass($data[$name]);
             $targetId = $this->uow->getEntityIdentifier($data[$name]);
             $data[$name] = new AssociationCacheEntry($targetClass, $targetId);
             continue;
         }
         // handle association identifier
         $targetId = is_object($data[$name]) && $this->uow->isInIdentityMap($data[$name]) ? $this->uow->getEntityIdentifier($data[$name]) : $data[$name];
         // @TODO - fix it !
         // handle UnitOfWork#createEntity hash generation
         if (!is_array($targetId)) {
             $data[reset($assoc['joinColumnFieldNames'])] = $targetId;
             $targetEntity = $this->em->getClassMetadata($assoc['targetEntity']);
             $targetId = array($targetEntity->identifier[0] => $targetId);
         }
         $data[$name] = new AssociationCacheEntry($assoc['targetEntity'], $targetId);
     }
     return new EntityCacheEntry($metadata->name, $data);
 }