public function getDependencyPhpExtensions()
    {
        if (is_array($this->_dependencyPhpExtensions)) return $this->_dependencyPhpExtensions;
        $this->_dependencyPhpExtensions = array();
        if (!isset($this->_packageXml->dependencies->required->extension)) {
            return $this->_dependencyPhpExtensions;
        }
        foreach($this->_packageXml->dependencies->required->extension as $_package) {
            $this->_dependencyPhpExtensions[] = array(
                'name'    => (string)$_package->name,
                'min'     => (string)$_package->min,
                'max'     => (string)$_package->max,
            );
        }
        return $this->_dependencyPhpExtensions;
    }