public function remove($attrs)
    {
        !is_array($attrs) && $attrs = array('id' => $attrs);
        
        foreach ($this->members() as $k => $m) {
            foreach ($attrs as $a => $v) {
                if ($m->getAttribute($a) != $v)
                    continue 2;
            }
            unset($this->members[$k]);
        }
        $this->members = array_values($this->members);
        return $this;
    }