function addFunction($type, $version, $name = '', $mirror = false)
    {
        if ($mirror) {
            return $this->addMirrorFunction($mirror, $type, $version, $name);
        }

        $set = array('attribs' => array('version' => $version), '_content' => $name);
        if (!isset($this->_channelInfo['servers']['primary'][$type]['function'])) {
            if (!isset($this->_channelInfo['servers'])) {
                $this->_channelInfo['servers'] = array('primary' =>
                    array($type => array()));
            } elseif (!isset($this->_channelInfo['servers']['primary'])) {
                $this->_channelInfo['servers']['primary'] = array($type => array());
            }

            $this->_channelInfo['servers']['primary'][$type]['function'] = $set;
            $this->_isValid = false;
            return true;
        } elseif (!isset($this->_channelInfo['servers']['primary'][$type]['function'][0])) {
            $this->_channelInfo['servers']['primary'][$type]['function'] = array(
                $this->_channelInfo['servers']['primary'][$type]['function']);
        }

        $this->_channelInfo['servers']['primary'][$type]['function'][] = $set;
        return true;
    }