code: func NewEchoResponse() *EchoResponse {
  	er := &EchoResponse{
  		Version: "1.0",
  		Response: EchoRespBody{
  			ShouldEndSession: true,
  		},
  		SessionAttributes: make(map[string]interface{}),
  	}
  
  	return er
  }
docs: // Response Functions
  // NewEchoResponse will construct a new response instance with the required metadata and an empty speech string.
  // By default the response will indicate that the session should be ended. Use the `EndSession(bool)` method if the
  // session should be left open.