add needed files

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

message.go

@@ -0,0 +1,40 @@
+package drpc
+
+import (
+	"github.com/unistack-org/micro/v3/client"
+)
+
+type drpcEvent struct {
+	payload     interface{}
+	topic       string
+	contentType string
+}
+
+func newDRPCEvent(topic string, payload interface{}, contentType string, opts ...client.MessageOption) client.Message {
+	var options client.MessageOptions
+	for _, o := range opts {
+		o(&options)
+	}
+
+	if len(options.ContentType) > 0 {
+		contentType = options.ContentType
+	}
+
+	return &drpcEvent{
+		payload:     payload,
+		topic:       topic,
+		contentType: contentType,
+	}
+}
+
+func (d *drpcEvent) ContentType() string {
+	return d.contentType
+}
+
+func (d *drpcEvent) Topic() string {
+	return d.topic
+}
+
+func (d *drpcEvent) Payload() interface{} {
+	return d.payload
+}