unittest\Output::backtrace PHP Method

    public function backtrace($backtrace, $type = self::ERROR)
    {
        $endtrace = '';
        for ($a = 0; $a != count($backtrace); $a++) {
            if (isset($backtrace[$a]['file']) && isset($backtrace[$a]['line'])) {
                $endtrace .= sprintf("{%s} - %s %s %s\n", $a, $backtrace[$a]['file'], $backtrace[$a]['line'], $backtrace[$a]['function']);
            }
        }
        $this->send($endtrace, $type);
    }