subscription

Subscription represents a stream of events. The carrier of the events is typically a channel, but isn't part of the interface.

Subscriptions can fail while established. Failures are reported through an error channel. It receives a value if there is an issue with the subscription (e.g. the network connection delivering the events has been closed). Only one value will ever be sent.

The error channel is closed when the subscription ends successfully (i.e. when the source of events is closed). It is also closed when Unsubscribe is called. The Unsubscribe method cancels the sending of events. You must call Unsubscribe in all cases to ensure that resources related to the subscription are released. It can be called any number of times.