Refactor errros package

errors/errors.go

@@ -1,13 +1,5 @@
 package errors
 
-type NotFoundError struct {
-	Message string
-}
-
-func (err NotFoundError) Error() string {
-	return err.Message
-}
-
 type UnknownError struct {
 	Err error
 }
@@ -16,6 +8,18 @@ func (err UnknownError) Error() string {
 	return err.Err.Error()
 }
 
+func (err UnknownError) Unwrap() error {
+	return err.Err
+}
+
+type NotFoundError struct {
+	Message string
+}
+
+func (err NotFoundError) Error() string {
+	return err.Message
+}
+
 type AlreadyExistsError struct {
 	Message string
 }