Checks out the document and returns the object ID of the PWC (private working copy).

@return ObjectIdInterface|null PWC object ID
179337
public function checkOut()
    {
        $newObjectId = $this->getId();

        $this->getBinding()->getVersioningService()->checkOut($this->getRepositoryId(), $newObjectId);

        if ($newObjectId === null) {
            return null;
        }

        return $this->getSession()->createObjectId($newObjectId);
    }
321960
public function getId()
	{
		if (is_object($this->id) && method_exists($this->id, '__toString')) {
			return (string) $this->id;
		}

		return $this->id;
	}
99952
protected function getDirname()
    {
        if (null === $this->dirname) {
            $r = new ReflectionObject($this);
            $this->dirname = dirname($r->getFileName());
        }

        return $this->dirname;
    }
351693
public function getPID()
    {
        $id = (string) $this->objectID;

        // PID is stored as little-endian, flip it around
        $pid = substr($id, 16, 2) . substr($id, 14, 2);
        return hexdec($pid);
    }
321690
function contentObject()
    {
        if ( $this->ContentObject === null )
        {
            if ( $this->ContentObjectID == 0 )
            {
                return null;
            }
            $this->ContentObject = eZContentObject::fetch( $this->ContentObjectID );
        }
        return $this->ContentObject;
    }
100946
public function getEditObject()
    {
        $soxId = $this->getEditObjectId();
        if ($this->_oEditObject === null && isset($soxId) && $soxId != "-1") {
            $this->_oEditObject = oxNew(\OxidEsales\Eshop\Application\Model\OrderFileList::class);
            $this->_oEditObject->loadOrderFiles($soxId);
        }

        return $this->_oEditObject;
    }
473134
public function find($id, int $lockMode = LockMode::NONE, ?int $lockVersion = null) : ?object
    {
        if ($id === null) {
            return null;
        }

        /* TODO: What if the ID object has a field with the same name as the
         * class' mapped identifier field name?
         */
        if (is_array($id)) {
            [$identifierFieldName] = $this->class->getIdentifierFieldNames();

            if (isset($id[$identifierFieldName])) {
                $id = $id[$identifierFieldName];
            }
        }

        // Check identity map first
        $document = $this->uow->tryGetById($id, $this->class);
        if ($document) {
            if ($lockMode !== LockMode::NONE) {
                $this->dm->lock($document, $lockMode, $lockVersion);
            }

            return $document; // Hit!
        }

        $criteria = ['_id' => $id];

        if ($lockMode === LockMode::NONE) {
            return $this->getDocumentPersister()->load($criteria);
        }

        if ($lockMode === LockMode::OPTIMISTIC) {
            if (! $this->class->isVersioned) {
                throw LockException::notVersioned($this->documentName);
            }

            $document = $this->getDocumentPersister()->load($criteria);
            if ($document) {
                $this->uow->lock($document, $lockMode, $lockVersion);
            }

            return $document;
        }

        return $this->getDocumentPersister()->load($criteria, null, [], $lockMode);
    }
706446
public function getId()
    {
        if (is_null($this->_id)) {
            $this->_id = md5(microtime() . mt_rand());
        }

        return $this->_id;
    }
171014
public function getIdentifier()
    {
        $identifierAttribute = $this->getFamily()->getAttributeAsIdentifier();
        if ($identifierAttribute) {
            /** @noinspection ExceptionsAnnotatingAndHandlingInspection */

            return $this->get($identifierAttribute->getCode());
        }

        return $this->getId();
    }
555061
public function getViewId()
    {
        if (!isset($this->_sViewId)) {
            $this->_sViewId = parent::getViewId() . '|' . \OxidEsales\Eshop\Core\Registry::getConfig()->getRequestParameter('oxcid');
        }

        return $this->_sViewId;
    }
386045
public function getElementId()
    {
        $id = $this->getAttribute('elementId');
        if (null === $id && null !== $this->element) {
            $id = $this->elementId = $this->element->id;
        }

        return $id;
    }
1242625
public function getWorkflowRequestObject()
    {
        if ($this->wrID > 0) {
            $cat = WorkflowProgressCategory::getByID($this->wpCategoryID);
            $handle = $cat->getWorkflowProgressCategoryHandle();
            $class = '\\Core\\Workflow\\Request\\' . Core::make('helper/text')->camelcase($handle) . 'Request';
            $pkHandle = $cat->getPackageHandle();
            $class = core_class($class, $pkHandle);
            $wr = $class::getByID($this->wrID);
            if (is_object($wr)) {
                $wr->setCurrentWorkflowProgressObject($this);

                return $wr;
            }
        }
    }
1219114
public function key()
    {
        // TODO: Track position internally to avoid repeated info() calls
        if ( ! $this->useIdentifierKeys) {
            $info = $this->mongoCursor->info();

            return isset($info['at']) ? $info['at'] : null;
        }

        return $this->mongoCursor->key();
    }
1082939
public function getObject()
    {
        if (null === $this->_identifier || null === $this->_class) {
            return;
        }

        return $this->_em->getRepository($this->_class)->find($this->_identifier);
    }
378921
public String getCopyModelReplaceId() {

        String result = null;
        if ((m_containerData.getMaxElements() == 1)
            && (m_overflowingElement != null)
            && (m_overflowingElement instanceof CmsContainerPageElementPanel)
            && (getFormerModelGroupParent() != null)) {
            result = ((CmsContainerPageElementPanel)m_overflowingElement).getId();
        }
        return result;
    }
934505
public function getFrontEndDataObject()
    {
        $obj = null;
        $ba = $this->BaseAction();

        if ($ba->hasMethod('getFrontEndDataObject')) {
            $obj = $ba->getFrontEndDataObject();
        } else {
            $obj = $this->Workflow()->getTarget();
        }

        return $obj;
    }
546567
public function getElementId()
    {
        if (null === $this->elementId && null !== $this->element) {
            $this->elementId = $this->element->id;
        }

        return $this->elementId;
    }