public function parse_request( $extra_query_vars = '' ) {
    global $wp_rewrite;

    
/**
 * Filters whether to parse the request.
 *
 * @since 3.5.0
 *
 * @param bool         $bool             Whether or not to parse the request. Default true.
 * @param WP           $this             Current WordPress environment instance.
 * @param array|string $extra_query_vars Extra passed query variables.
 */
    if ( ! apply_filters( 'do_parse_request', true, $this, $extra_query_vars ) ) {
      return;
    }

    $this->query_vars     = array();
    $post_type_query_vars = array();

    if ( is_array( $extra_query_vars ) ) {
      $this->extra_query_vars = & $extra_query_vars;
    } elseif ( ! empty( $extra_query_vars ) ) {
      parse_str( $extra_query_vars, $this->extra_query_vars );
    }
    // Process PATH_INFO, REQUEST_URI, and 404 for permalinks.

    // Fetch the rewrite rules.
    $rewrite = $wp_rewrite->wp_rewrite_rules();

    if ( ! empty( $rewrite ) ) {
      // If we match a rewrite rule, this will be cleared.
      $error               = '404';
      $this->did_permalink = true;

      $pathinfo         = isset( $_SERVER['PATH_INFO'] ) ? $_SERVER['PATH_INFO'] : '';
      list( $pathinfo ) = explode( '?', $pathinfo );
      $pathinfo         = str_replace( '%', '%25', $pathinfo );

      list( $req_uri ) = explode( '?', $_SERVER['REQUEST_URI'] );
      $self            = $_SERVER['PHP_SELF'];
      $home_path       = trim( parse_url( home_url(), PHP_URL_PATH ), '/' );
      $home_path_regex = sprintf( '|^%s|i', preg_quote( $home_path, '|' ) );

      /*
			 * Trim path info from the end and the leading home path from the front.
			 * For path info requests, this leaves us with the requesting filename, if any.
			 * For 404 requests, this leaves us with the requested permalink.
			 */
      $req_uri  = str_replace( $pathinfo, '', $req_uri );
      $req_uri  = trim( $req_uri, '/' );
      $req_uri  = preg_replace( $home_path_regex, '', $req_uri );
      $req_uri  = trim( $req_uri, '/' );
      $pathinfo = trim( $pathinfo, '/' );
      $pathinfo = preg_replace( $home_path_regex, '', $pathinfo );
      $pathinfo = trim( $pathinfo, '/' );
      $self     = trim( $self, '/' );
      $self     = preg_replace( $home_path_regex, '', $self );
      $self     = trim( $self, '/' );

      // The requested permalink is in $pathinfo for path info requests and
      // $req_uri for other requests.
      if ( ! empty( $pathinfo ) && ! preg_match( '|^.*' . $wp_rewrite->index . '$|', $pathinfo ) ) {
        $requested_path = $pathinfo;
      } else {
        // If the request uri is the index, blank it out so that we don't try to match it against a rule.
        if ( $req_uri == $wp_rewrite->index ) {
          $req_uri = '';
        }
        $requested_path = $req_uri;
      }
      $requested_file = $req_uri;

      $this->request = $requested_path;

      // Look for matches.
      $request_match = $requested_path;
      if ( empty( $request_match ) ) {
        // An empty request could only match against ^$ regex.
        if ( isset( $rewrite['$'] ) ) {
          $this->matched_rule = '$';
          $query              = $rewrite['$'];
          $matches            = array( '' );
        }
      } else {
        foreach ( (array) $rewrite as $match => $query ) {
          // If the requested file is the anchor of the match, prepend it to the path info.
          if ( ! empty( $requested_file ) && strpos( $match, $requested_file ) === 0 && $requested_file != $requested_path ) {
            $request_match = $requested_file . '/' . $requested_path;
          }

          if ( preg_match( "#^$match#", $request_match, $matches ) ||
            preg_match( "#^$match#", urldecode( $request_match ), $matches ) ) {

            if ( $wp_rewrite->use_verbose_page_rules && preg_match( '/pagename=\$matches\[([0-9]+)\]/', $query, $varmatch ) ) {
              // This is a verbose page match, let's check to be sure about it.
              $page = get_page_by_path( $matches[ $varmatch[1] ] );
              if ( ! $page ) {
                continue;
              }