public static bool Delete(MolUser user)
        {
            var found = _usersList.Exists(usr => usr.Id == user.Id);

            if (found)
            {
                _usersList.Remove(_usersList.Find(usr => usr.Id == user.Id));
                return(true);
            }
            return(false);
        }
 public static bool Add(MolUser user)
 {
     _usersList.Add(user);
     return(true);
 }