apply f and send result to channels processor.
shortcut for blocking read.
shortcut for blocking write.
'blocking' write of 'a' to channel.
'blocking' write of 'a' to channel. Note, that this method can be called only inside 'go' or 'async' blocks, since blocking is emulated by 'Async.await'
Entity, which can 'eat' objects of type A, can be part of channel