subscribes current user to a thread, or ignore thread. Subscribing to a thread is unnecessary if the user is already subscribed to the repository. Ignoring a thread will mute all future notifications (until you comment or get at-mentioned).
set.thread.notifications.subscription(id, ..., ctx = get.github.context())
the thread id
extra parameters. See http://developer.github.com/v3/activity/notifications/#set-a-thread-subscription for details.
the github context object
the response object