public function setDependencyPhpVersion($minVersion, $maxVersion)
    {
        $parent = $this->_packageXml->dependencies;
        $parent = $this->_getNode('required', $parent);
        $parent = $this->_getNode('php', $parent);
        $parent->addChild('min', $minVersion);
        $parent->addChild('max', $maxVersion);
        return $this;
    }