public function debug($msg = true, $file = null, $line = null)
    {
        if (is_bool($msg)) {
            $this->debug = $msg;

            return $this;
        }

        if (is_object($msg)) {
            throw $this->exception('Do not debug objects');
        }

        // The rest of this method is obsolete
        if ((isset($this->debug) && $this->debug)
            || (isset($this->app->debug) && $this->app->debug)
        ) {
            $this->app->outputDebug($this, $msg, $file/*, $line*/);
        }
    }