ResponsibleList::getAccesibleUsers

public function getAccesibleUsers(): ?array
{
	// department members
	$userIds = $this->getDepartmentMembers();
	$this->getNonDepartmentMembers();
	// department manager
	if ($this->user->getPermission(PermissionDictionary::TASK_DEPARTMENT_MANAGER_DIRECT))
	{
		$userIds = array_merge($userIds, $this->getDepartmentManager());
	}
	// non department managers
	if ($this->user->getPermission(PermissionDictionary::TASK_NON_DEPARTMENT_MANAGER_DIRECT))
	{
		$userIds = array_merge($userIds, $this->getNonDepartmentManager());
	}
	// all other users
	if ($this->user->getPermission(PermissionDictionary::TASK_NON_DEPARTMENT_DIRECT))
	{
		$userIds = array_merge($userIds, $this->getNonDepartmentMembers());
	}

	return $userIds;
}