SenseNet.ContentRepository.Group.AssertValidMembers C# (CSharp) Method

        protected void AssertValidMembers()
        {
            //only check existing groups
            if (this.Id == 0)
                return;

            if (RepositoryConfiguration.SpecialGroupNames.Contains(this.Name))
            {
                if (this.Members.Count() > 0)
                    throw new InvalidOperationException(string.Format("The {0} group is a special system group, members cannot be added to it.", this.DisplayName));
            }

            foreach (var member in this.Members)
            {
                var group = member as Group;
                if (group == null)
                    continue;

                if (group.Id == this.Id)
                    throw new InvalidOperationException(string.Format("Group cannot contain itself as a member. Please remove {0} from the Members list.", this.DisplayName));

                if (this.Security.IsInGroup(group.Id))
                    throw new InvalidOperationException(string.Format("Circular group membership is not allowed. Please remove {0} from the Members list.", group.DisplayName));
            }
        }