code: func (m *VerifyMessageRequest) MarshalJSON() ([]byte, error) {
  	return json.Marshal(struct {
  		APIKey    string `json:"api_key"`
  		APISecret string `json:"api_secret"`
  		VerifyMessageRequest
  	}{
  		APIKey:               m.apiKey,
  		APISecret:            m.apiSecret,
  		VerifyMessageRequest: *m,
  	})
  }
docs: // MarshalJSON returns a byte slice with the serialized JSON of the
  // VerifyMessageRequest struct.