private function updatePeakMemoryUsage ()
	{
		$memory = memory_get_peak_usage ();
		if ($memory > $this->peakMemoryUsage)
		{
			$this->peakMemoryUsage = $memory;
			$this->setParameter ('Memory/PeakMemoryUsage', $memory);

			if (extension_loaded ('newrelic'))
			{
				newrelic_custom_metric ('Custom/PeakMemoryUsage', $memory);
			}
		}
	}