public FriendModel GetUserById(string userId) { Func <FriendModel, bool> predicate = user => user.Id.Equals(userId); var result = Friends.FirstOrDefault(predicate); if (result == null) { result = Pending.FirstOrDefault(predicate); } if (result == null) { result = Blocked.FirstOrDefault(predicate); } if (result == null) { result = Requested.FirstOrDefault(predicate); } return(result); }