public List <User> List()
        {
            var usersResponse = new List <User> ();

            using (SqlConnection conn = new SqlConnection(ConnectionString())) {
                using (var cmd = new SqlCommand()) {
                    cmd.Connection  = conn;
                    cmd.CommandText = _userSql.SqlList();
                    cmd.CommandType = CommandType.Text;

                    conn.Open();
                    using (DbDataReader dr = cmd.ExecuteReader()) {
                        while (dr.Read())
                        {
                            User user = new User();
                            user.Id    = Convert.ToInt32(dr["Id"].ToString());
                            user.Name  = dr["Name"].ToString();
                            user.Email = dr["Email"].ToString();

                            usersResponse.Add(user);
                        }
                    }
                }
            }

            return(usersResponse);
        }