public void InitFriends(User user)
        {
            var userChatGroups = UserChatGroups.Where(x => x.UserId == user.Id).ToList();

            user.Friends = new List <User>();

            foreach (var userChatGroup in userChatGroups)
            {
                user.Friends.Add(Users.Single(y => y.Id == UserChatGroups.Single(x => x.ChatGroupId == userChatGroup.ChatGroupId && x.UserId != user.Id).UserId));
            }
        }
 public void InitUserChatGroups(User user)
 {
     user.UserChatGroups = UserChatGroups.Where(x => x.UserId == user.Id).ToList();
 }