private function checkUntrackedClassPropertyAmount() : string { $untrackedPropertyList = PropertyFilter::filterUntrackedClassPropertyList($this->propertyList, $this->getTrackedPropertyTypeList()); $untrackedPropertyAmount = count($untrackedPropertyList); if ($untrackedPropertyAmount > $this->untrackedMaxCount) { $message = 'You have %d properties declared of %s type, must be less or equals than %d properties in total'; $error = sprintf($message, $untrackedPropertyAmount, 'object instance', $this->untrackedMaxCount); return $error; } return ''; }