public function _getOptions()
    {
        $opts = array();
        if (!empty($this->where))
        {
            $opts['where'] = $this->where;
        }
        if (count($this->includes))
        {
            $opts['include'] = join(',', $this->includes);
        }
        if (count($this->selectedKeys))
        {
            $opts['keys'] = join(',', $this->selectedKeys);
        }
        if ($this->limit >= 0)
        {
            $opts['limit'] = $this->limit;
        }
        if ($this->skip > 0)
        {
            $opts['skip'] = $this->skip;
        }
        if ($this->orderBy)
        {
            $opts['order'] = join(',', $this->orderBy);
        }
        if ($this->count)
        {
            $opts['count'] = $this->count;
        }

        return $opts;
    }