public static function init($data_directory = null)
	{
		$coverage_tool = new self($data_directory);
		$mode = isset($_GET['rct_mode']) ? $_GET['rct_mode'] : '';

		if ( $mode == 'output' ) {
			echo $coverage_tool->aggregateCoverageInformation();
		}
		else {
			$coverage_tool->startCollection();
			register_shutdown_function(array($coverage_tool, 'stopCollection'));
		}
	}