code: function get_route_crossroads(pageInfo, {can_be_null=false}={}) {
      assert_internal([true, false].includes(can_be_null));
      assert_page_info(pageInfo, {can_be_null});
      const {route} = pageInfo;
      if( can_be_null && ! route ) {
          return null;
      }
      assert_internal(route);
      const route_crossroad = parse_route_string(route);
      return route_crossroad;
  }
docs: /*
  function getRouteString() {
  const route_crossroad = parse_route_string(route);
  return route_crossroad._pattern;
  }