code: protected function mapParams(array $params) : array
      {
          unset($params[0]);
          foreach ($params as $name => $value) {
              if (!is_string($name)) {
                  unset($params[$name]);
              } else {
                  $params[$name] = urldecode($value[0]);
              }
          }
  
          return $params;
      }
docs: Maps resulting params of a regex match to name=>value array.
  
  @param array $params
  @return array