code: public function end()
      {
          $this->_duration = microtime(true) - $this->_startTime;
          $this->_average = $this->_duration / $this->_repeat;
          $this->_rate = $this->_repeat / $this->_duration;
          $this->_memory = memory_get_usage(true) - $this->_startMemory;
      }
docs: Stops the timer.