public function serializerFactories(Serializer\Factory\Group $factories = NULL)
{
if (isset($factories)) {
$this->_serializerFactories = $factories;
} elseif (NULL === $this->_serializerFactories) {
$this->_serializerFactories = \FluentDOM::getSerializerFactories();
}
return $this->_serializerFactories;
}