package client type message struct { topic string contentType string payload interface{} } func newMessage(topic string, payload interface{}, contentType string) Message { return &message{ payload: payload, topic: topic, contentType: contentType, } } func (m *message) ContentType() string { return m.contentType } func (m *message) Topic() string { return m.topic } func (m *message) Payload() interface{} { return m.payload }