code: func (r *Route) GetQueriesTemplates() ([]string, error) {
  	if r.err != nil {
  		return nil, r.err
  	}
  	if r.regexp.queries == nil {
  		return nil, errors.New("mux: route doesn't have queries")
  	}
  	var queries []string
  	for _, query := range r.regexp.queries {
  		queries = append(queries, query.template)
  	}
  	return queries, nil
  }
docs: // GetQueriesTemplates returns the templates used to build the
  // query matching.
  // This is useful for building simple REST API documentation and for instrumentation
  // against third-party services.
  // An error will be returned if the route does not define queries.