src/log4php/appenders/LoggerAppenderPDO.php
protected function format(LoggerLoggingEvent $event) {
		$params = array();
		foreach($this->converters as $converter) {
			$buffer = '';
			while ($converter !== null) {
				$converter->format($buffer, $event);
				$converter = $converter->next;
			}
			$params[] = $buffer;
		}
		return $params;
	}
protected function format(LoggerLoggingEvent $event) {
		$params = array();
		foreach($this->converters as $converter) {
			$buffer = '';
			while ($converter !== null) {
				$converter->format($buffer, $event);
				$converter = $converter->next;
			}
			$params[] = $buffer;
		}
		return $params;
	}
Converts the logging event to a series of database parameters by using
the converter chain which was set up on activation.