code: function(fragment, forcePushState) {
        if (fragment == null) {
          if (this._hasPushState || !this._wantsHashChange || forcePushState) {
            fragment = this.location.pathname;
            var root = this.root.replace(trailingSlash, '');
            if (!fragment.indexOf(root)) fragment = fragment.slice(root.length);
          } else {
            fragment = this.getHash();
          }
        }
        return fragment.replace(routeStripper, '');
      }
docs: Get the cross-browser normalized URL fragment, either from the URL, the hash, or the override.