create project and customercontroller

AB.Domain/Exceptions/BusinessPartnerNotFoundException.cs

@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace AB.Domain.Exceptions
+{
+    public class BusinessPartnerNotFoundException : NotFoundException
+    {
+
+        public BusinessPartnerNotFoundException(Guid businessPartnerId)
+        : base ($"The BusinessPartner with the indetifier {businessPartnerId} was not found.")
+            { }
+
+    }
+}