public IActionResult Get(int key)
        {
            DefaultBatchCustomer customers = _customers.FirstOrDefault(c => c.Id == key);

            if (customers == null)
            {
                return(BadRequest());
            }

            return(Ok(customers));
        }
 public IActionResult Post([FromBody] DefaultBatchCustomer customer)
 {
     _customers.Add(customer);
     return(Created(customer));
 }