Doctrine\ODM\MongoDB\Mapping\ClassMetadataInfo::setLockMapping PHP Method

    public function setLockMapping(array &$mapping)
    {
        if ($mapping['type'] !== 'int') {
            throw LockException::invalidLockFieldType($mapping['type']);
        }
        $this->isLockable = true;
        $this->lockField = $mapping['fieldName'];
    }