protected static function configureLogging()
    {
        if (self::$logger === null) {
            if (isset(self::$configuration['log']) && is_array(self::$configuration['log']) && count(self::$configuration['log'])) {
                include_once 'Log.php'; // PEAR Log class
                $c = self::$configuration['log'];
                $type = isset($c['type']) ? $c['type'] : 'file';
                $name = isset($c['name']) ? $c['name'] : './propel.log';
                $ident = isset($c['ident']) ? $c['ident'] : 'propel';
                $conf = isset($c['conf']) ? $c['conf'] : array();
                $level = isset($c['level']) ? $c['level'] : PEAR_LOG_DEBUG;
                self::$logger = Log::singleton($type, $name, $ident, $conf, $level);
            } // if isset()
        }
    }