code: func Media(val interface{}, viewName ...string) {
  	if r, ok := responseDefinition(); ok {
  		if m, ok := val.(*design.MediaTypeDefinition); ok {
  			if m != nil {
  				r.MediaType = m.Identifier
  			}
  		} else if identifier, ok := val.(string); ok {
  			r.MediaType = identifier
  		} else {
  			dslengine.ReportError("media type must be a string or a pointer to MediaTypeDefinition, got %#v", val)
  		}
  		if len(viewName) == 1 {
  			r.ViewName = viewName[0]
  		} else if len(viewName) > 1 {
  			dslengine.ReportError("too many arguments given to DefaultMedia")
  		}
  	}
  }
docs: // Media can be used in: Response, ResponseTemplate
  //
  // Media sets a response media type by name or by reference using a value returned by MediaType:
  //
  //	Response("NotFound", func() {
  //		Status(404)
  //		Media("application/json")
  //	})
  //
  // If Media uses a media type defined in the design then it may optionally specify a view name:
  //
  //	Response("OK", func() {
  //		Status(200)
  //		Media(BottleMedia, "tiny")
  //	})
  //
  // Specifying a media type is useful for responses that always return the same view.