private static function traceUnshift(&$trace, $class, $file, $line)
{
if (isset($trace[0]['file'], $trace[0]['line']) && $trace[0]['file'] === $file && $trace[0]['line'] === $line) {
return;
}
array_unshift($trace, array('function' => $class ? 'new ' . $class : null, 'file' => $file, 'line' => $line));
}