public void RemoveChildGroup(UserGroup group)
{
if (!children.Contains(group))
{
throw new InvalidOperationException("The user group is not a child of this parent");
}
children.Remove(group);
group.Parent = null;
}
public void AddChildGroup(UserGroup group)
{
if (children.Contains(group))
{
throw new InvalidOperationException("The user group already belongs to this parent");
}
children.Add(group);
group.Parent = this;
}