public function _function($from, $to, $action)
{
switch ($action) {
case static::ACT_CONVERT_TO_OBJECT:
/* @var $from Entity\ScalingMetric */
if (!empty($from->calcFunction)) {
$to->function = static::$functionMap[$from->calcFunction];
}
break;
case static::ACT_CONVERT_TO_ENTITY:
/* @var $to Entity\ScalingMetric */
$to->calcFunction = $this->functionToEntity($from);
break;
case static::ACT_GET_FILTER_CRITERIA:
return [['calcFunction' => $this->functionToEntity($from)]];
}
}