StreamChannelTransformer<S, T> class

A StreamChannelTransformer transforms the events being passed to and emitted by a StreamChannel.

This works on the same principle as StreamTransformer and StreamSinkTransformer. Each transformer defines a bind method that takes in the original StreamChannel and returns the transformed version.

Transformers must be able to have bind called multiple times. If a subclass implements bind explicitly, it should be sure that the returned stream follows the second stream channel guarantee: closing the sink causes the stream to close before it emits any more events. This guarantee is invalidated when an asynchronous gap is added between the original stream's event dispatch and the returned stream's, for example by transforming it with a StreamTransformer. The guarantee can be easily preserved using StreamChannel.withCloseGuarantee.