code: public function updateStats($stats, $delta = 1, $sampleRate = 1)
      {
          if (!is_array($stats)) {
              $stats = array($stats);
          }
          $data = array();
          foreach ($stats as $stat) {
              $data[$stat] = "$delta|c";
          }
  
          $this->queue($data, $sampleRate);
      }
docs: Updates one or more stats counters by arbitrary amounts.
  
  @param string|array $stats      The metric(s) to update. Should be either a string or array of metrics.
  @param int|1        $delta      The amount to increment/decrement each metric by.
  @param float|1      $sampleRate the rate (0-1) for sampling.
  
  @return boolean