public async Task <bool> ClearGroupForUnitsAsync(int departmentGroupId, CancellationToken cancellationToken = default(CancellationToken))
{
if (departmentGroupId <= 0)
{
throw new ArgumentException("DepartmentGroupId cannot be null", "departmentGroupId");
}
var units = await _unitsRepository.GetAllUnitsByGroupIdAsync(departmentGroupId);
foreach (var unit in units)
{
unit.StationGroupId = null;
unit.StationGroup = null;
await _unitsRepository.SaveOrUpdateAsync(unit, cancellationToken);
}
return(true);
}