public IActionResult GetInvoicesByInvoiceId(int invoiceId) { var invoicesByInvoiceId = _repository.GetInvoicesByInvoiceId(invoiceId); var noInvoicesByInvoiceId = !invoicesByInvoiceId.Any(); if (noInvoicesByInvoiceId) { return(NotFound("There are currently no invoices matching this invoice id.")); } return(Ok(invoicesByInvoiceId)); }