code: public function parseRequest($request)
      {
          if ($this->enablePrettyUrl) {
              $pathInfo = $request->getPathInfo();
              /* @var $rule UrlRule */
              foreach ($this->rules as $rule) {
                  if (($result = $rule->parseRequest($this, $request)) !== false) {
                      return $result;
                  }
              }
  
              if ($this->enableStrictParsing) {
                  return false;
              }
  
              Yii::trace('No matching URL rules. Using default URL parsing logic.', __METHOD__);
  
              $suffix = (string) $this->suffix;
              if ($suffix !== '' && $pathInfo !== '') {
                  $n = strlen($this->suffix);
                  if (substr_compare($pathInfo, $this->suffix, -$n, $n) === 0) {
                      $pathInfo = substr($pathInfo, 0, -$n);
                      if ($pathInfo === '') {
                          // suffix alone is not allowed
                          return false;
                      }
                  } else {
                      // suffix doesn't match
                      return false;
                  }
              }
  
              return [$pathInfo, []];
          } else {
              Yii::trace('Pretty URL not enabled. Using default URL parsing logic.', __METHOD__);
              $route = $request->getQueryParam($this->routeParam, '');
              if (is_array($route)) {
                  $route = '';
              }
  
              return [(string) $route, []];
          }
      }
docs: Parses the user request.
  @param Request $request the request component
  @return array|boolean the route and the associated parameters. The latter is always empty
  if [[enablePrettyUrl]] is false. False is returned if the current request cannot be successfully parsed.