public function getTotal()
    {
        if (is_null($this->_total)) {
            if (($total = $this->predictTotal())) {
                $this->_total = $total;
            } elseif (isset($this->_items)) {
                return count($this->_items);
            } else {
                $this->_total = false;
            }
        }

        return $this->_total;
    }