/**
* Ensure we have the query data.
*
* @return NULL
*/
private function _init()
{
if ($this->_mapping !== null) {
return;
}
if ($this->_data_cache->hasQuery(self::PREFS)) {
$this->_mapping = $this->_data_cache->getQuery(self::PREFS);
} else {
$this->synchronize();
}
}