code: protected function clearParams(&$params)
      {
          foreach ($params as $key => &$value) {
              if (is_array($value)) {
                  $this->clearParams($value);
              } elseif ($value === '') {
                  unset($params[$key]);
              }
          }
      }
docs: [[@doctodo method_description:clearParams]].
  
  @param [[@doctodo param_type:params]] $params [[@doctodo param_description:params]]