public protocol WriteObservingByteToMessageDecoder : ByteToMessageDecoder

Some ByteToMessageDecoders need to observe writes (which are outbound events). ByteToMessageDecoders which implement the WriteObservingByteToMessageDecoder protocol will be notified about every outbound write.

WriteObservingByteToMessageDecoder may only observe a write and must not try to transform or block it in any way. After the write method returns the write will be forwarded to the next outbound handler.