Pheasant\Identity::__toString PHP Method

    public function __toString()
    {
        $array = $this->toArray();
        $keyValues = array_map(function ($k) use($array) {
            return sprintf('%s=%s', $k, $array[$k]);
        }, array_keys($array));
        return sprintf('%s[%s]', $this->_class, implode(',', $keyValues));
    }