code: func NewNegotiationHandler(logger logrus.FieldLogger) *NegotiationHandler {
  	return &NegotiationHandler{
  		json:  NewJSONWriter(logger),
  		plain: NewTextWriter(logger, "plain"),
  		html:  NewTextWriter(logger, "html"),
  		types: []string{
  			"application/json",
  		},
  	}
  }
docs: // NewNegotiationHandler creates a new NewNegotiationHandler.