channel.publish() now returns a DeferredConsumer object on which callbacks can be installed for handling returned messages,
channel.get().onSize() has a different behavior: it now reports the message size (and no longer the queue size),
channel.get().onCount() has been added: it reports the queue size (this used to be the onSize() method),
channel.consume().onSize() method has been added to find out the size of the upcoming message
Michael van der Werve
Emiel Bruijntjes
Marcin Gibula
Aart Stuurman