Checks whether there are values available to take from the hub.
Takes a value from the hub if there is one or else returns the specified default value.
Takes up to the specified number of values from the hub.
The current number of values available to take from the hub.
Unsubscribes this subscriber from the hub.
A
Subscription[A]is a subscription to receiveAvalues from the hub. The guarantee is that a subscriber will receive all values published to hub while it is subscribed.