internal void AddMembers(int groupId, IEnumerable <int> userMembers, IEnumerable <int> groupMembers, IEnumerable <int> parentGroups)
{
_dataProvider.AddMembers(groupId, userMembers, groupMembers);
if (parentGroups != null)
{
foreach (var parentGroupId in parentGroups.Distinct())
{
_dataProvider.AddMembers(parentGroupId, null, new[] { groupId });
}
}
}