protected function prepareKeys($models) {
		$keys = [];
		foreach ($models as $model) {
			$keys[] = $model->getPrimaryKey();
		}
		return $keys;
	}
protected function prepareKeys($models) {
		$keys = [];
		foreach ($models as $model) {
			$keys[] = $model->getPrimaryKey();
		}
		return $keys;
	}
protected function prepareKeys ( $ models ) { $ keys = [ ] ; foreach ( $ models as $ model ) { $ keys [ ] = $ model -> getPrimaryKey ( ) ; } return $ keys ; }
Prepares the keys associated with the currently available data models.
@param Model[] $models the available data models
@return array the keys
Prepares the keys associated with the currently available data models .