code: func (a *ActionDefinition) AllParams() *AttributeDefinition {
  	var res *AttributeDefinition
  	if a.Params != nil {
  		res = DupAtt(a.Params)
  	} else {
  		res = &AttributeDefinition{Type: Object{}}
  	}
  	if a.HasAbsoluteRoutes() {
  		return res
  	}
  	res = res.Merge(a.Parent.Params)
  	if p := a.Parent.Parent(); p != nil {
  		res = res.Merge(p.CanonicalAction().PathParams())
  	} else {
  		res = res.Merge(a.Parent.PathParams())
  	}
  	return res.Merge(Design.Params)
  }
docs: // AllParams returns the path and query string parameters of the action across all its routes.