public function getCompatible()
    {
        if (is_array($this->_compatible)) return $this->_compatible;
        $this->_compatible = array();
        if(!isset($this->_packageXml->compatible->package)) {
            return array();
        }
        foreach ($this->_packageXml->compatible->package as $_package) {
            $this->_compatible[] = array(
                'name'    => (string)$_package->name,
                'channel' => (string)$_package->channel,
                'min'     => (string)$_package->min,
                'max'     => (string)$_package->max
            );
        }
        return $this->_compatible;
    }