Measure::deleteAction

public function deleteAction(int $id): ?bool
{
	$existsResult = $this->exists($id);
	if (!$existsResult->isSuccess())
	{
		$this->addErrors($existsResult->getErrors());
		return null;
	}

	$r = parent::delete($id);
	if ($r->isSuccess())
	{
		return true;
	}
	else
	{
		$this->addErrors($r->getErrors());
		return null;
	}
}