public function read($url)
    {
        $xml = $this->requestXml($url, "/channel.xml");

        $channelName = (string) $xml->name;
        $channelAlias = (string) $xml->suggestedalias;

        $supportedVersions = array_keys($this->readerMap);
        $selectedRestVersion = $this->selectRestVersion($xml, $supportedVersions);
        if (!$selectedRestVersion) {
            throw new \UnexpectedValueException(sprintf('PEAR repository %s does not supports any of %s protocols.', $url, implode(', ', $supportedVersions)));
        }

        $reader = $this->readerMap[$selectedRestVersion['version']];
        $packageDefinitions = $reader->read($selectedRestVersion['baseUrl']);

        return new ChannelInfo($channelName, $channelAlias, $packageDefinitions);
    }