public function getAssignedUsers($deliveryId)
    {
        $users = [];
        foreach ($this->getInternalServices() as $service) {
            $users = array_merge($users, $service->getAssignedUsers($deliveryId));
        }

        return $users;
    }
public function getAssignedUsers($deliveryId)
    {
        $users = [];
        foreach ($this->getInternalServices() as $service) {
            $users = array_merge($users, $service->getAssignedUsers($deliveryId));
        }

        return $users;
    }
public function getAssignedUsers ( $ deliveryId ) { $ users = [ ] ; foreach ( $ this -> getInternalServices ( ) as $ service ) { $ users = array_merge ( $ users , $ service -> getAssignedUsers ( $ deliveryId ) ) ; } return $ users ; }
Returns the ids of users assigned to a delivery

@param string|\core_kernel_classes_Resource $deliveryId form|delivery instance or form id
@return string[] ids of users
Returns the ids of users assigned to a delivery