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

    public function getAssociationTargetClass($assocName)
    {
        if (!isset($this->associationMappings[$assocName])) {
            throw new InvalidArgumentException("Association name expected, '" . $assocName . "' is not an association.");
        }
        return $this->associationMappings[$assocName]['targetDocument'];
    }