code: function() {
            var url;
            if (this.get('sql_api_template')) {
              url = this.get("sql_api_template").replace('{user}', this.get('user_name'));
            } else {
              url = this.get('sql_api_protocol') + '://' +
                this.get('user_name') + '.' +
                this.get('sql_api_domain') + ':' +
                this.get('sql_api_port');
            }
            return url;
          }
docs: returns the base url to compose the final url
  http://user.carto.com/