code: func defaultRouteParams(a *design.ActionDefinition) *design.AttributeDefinition {
  	r := a.Routes[0]
  	params := r.Params()
  	o := make(design.Object, len(params))
  	nz := make(map[string]bool, len(params))
  	pparams := a.PathParams()
  	for _, p := range params {
  		o[p] = pparams.Type.ToObject()[p]
  		nz[p] = true
  	}
  	return &design.AttributeDefinition{Type: o, NonZeroAttributes: nz}
  }
docs: // defaultRouteParams returns the parameters needed to build the first route of the given action.