php back trace

class LogAdapter
{
    public static function log($event)
    {
        $bt = debug_backtrace();
        $index = null;
        foreach($bt as $idx => $trace) {
            if($trace['class'] == 'LogAdapter') {
                $index = $idx;
            }
        }
        echo $event . ' Class : ' . $bt[$index + 1]['class'] . ', line : ', $bt[0]['line'] . ', file : ' . $bt[$index + 1]['file'] . '<br />';
    }
}

class TestC
{
    public static function test()
    {
        LogAdapter::log('Event 2');
    }
}


class TestB {
    public static function test()
    {
        LogAdapter::log('Event 1');
        TestC::test();
        LogAdapter::log('Event 3');
    }

}
TestB::test();