public function draw()
    {
        $numberLen = strlen(' 100%');
        $complete = round($this->_progress / $this->_total, 2);
        $barLen = ($this->_width - $numberLen) * ($this->_progress / $this->_total);
        $bar = '';
        if ($barLen > 1) {
            $bar = str_repeat('=', $barLen - 1) . '>';
        }

        $pad = ceil($this->_width - $numberLen - $barLen);
        if ($pad > 0) {
            $bar .= str_repeat(' ', $pad);
        }
        $percent = ($complete * 100) . '%';
        $bar .= str_pad($percent, $numberLen, ' ', STR_PAD_LEFT);

        $this->_io->overwrite($bar, 0);

        return $this;
    }