public async Task <ActionResult> GetSaldo(Guid ContaId)
        {
            try
            {
                if (!ModelState.IsValid)
                {
                    return(BadRequest(ModelState)); // 400 bad request
                }

                var result = await _service.GetBalance(ContaId);

                return(Ok(result));
            }
            catch (ArgumentException ex)
            {
                return(StatusCode((int)HttpStatusCode.InternalServerError, ex.Message));
            }
        }