private function formatBacktrace()
{
$backtrace = '';
foreach ($this->event->getBacktrace() as $step) {
if (isset($step['line']) && isset($step['file'])) {
$backtrace .= "#{$step['line']} {$step['file']}";
$backtrace .= "<br />";
$backtrace .= PHP_EOL;
}
}
return rtrim($backtrace, "<br />" . PHP_EOL);
}