public function log($level, $message, array $context = [])
    {
        $message = $this->_format($message, $context);
        $output = date('Y-m-d H:i:s') . ' ' . ucfirst($level) . ': ' . $message;

        return (bool)$this->_output->write(sprintf('<%s>%s</%s>', $level, $output, $level));
    }