field checker test

fielder.go

@@ -148,7 +148,9 @@ func fieldVal(val reflect.Value, fieldName string, files RequestFiles, names ...
 				}
 			}
 			if !field.IsValid() {
+				log.Println("invalid")
 				if f, check := val.Interface().(IFieldChecker); check {
+					log.Println("ifieldchecker")
 					if check := f.RestFieldCheck(fieldName); check {
 						return true
 					}