code: private function debugKeyValues($key)
      {
          $values = array();
          // update 'collect and output'
          $requestKey = null;
          if (isset($_REQUEST['debug'])) {
              $requestKey = $_REQUEST['debug'];
          } elseif (isset($_COOKIE['debug'])) {
              $requestKey = $_COOKIE['debug'];
          }
          $isValidKey = $requestKey == $key;
          if ($isValidKey) {
              // only enable collect / don't disable it
              $values['collect'] = true;
          }
          $values['output'] = $isValidKey;
          return $values;
      }
docs: Test $_REQUEST['debug'] against passed key
  return collect & output values
  
  @param string $key secret key
  
  @return array