Helper::loadActivity

private function loadActivity(int $activityId, int $ownerTypeId, int $ownerId)
{
	if (!$ownerId || !\CCrmOwnerType::IsDefined($ownerTypeId))
	{
		return null;
	}

	$activity = \CCrmActivity::GetByID($activityId);
	if (!$activity || $activity['PROVIDER_ID'] !== 'CRM_CALENDAR_SHARING')
	{
		return null;
	}

	return $activity;
}