Youtube API：如果状态为getIsLinked为false，则将google客户端与youtube频道相关联

I'm able to get a list of google client channels and determine if channel linked with youtube or not using:

$response = $youtube->channels->listChannels('status', array('mine' => true));
$isLinked = $response[0]->getIsLinked();

But how do I link the channel if it is not linked? How do I make the channel privacy public?