Do not fail if builder not initialized

error.go

@@ -61,3 +61,12 @@ func (e *Error) Translate(ctx context.Context) string {
 
 	return printer.Sprintf(e.key, translatedParams...)
 }
+
+func (e *Error) Is(other error) bool {
+	switch err := other.(type) {
+	case *Error:
+		return e.key == err.key
+	}
+
+	return false
+}

translator.go

@@ -77,6 +77,10 @@ func GetPrinter(lang language.Tag) *message.Printer {
 
 func GetLanguages() []language.Tag {
 	if supportedLanguages == nil {
+		if builder == nil {
+			return nil
+		}
+
 		supportedLanguages = builder.Languages()
 
 		for idx := range supportedLanguages {