broker.go (2 lines):
	- line 1208: // TODO if decoded ID < cur ID, discard until we catch up
	- line 1209: // TODO if decoded ID > cur ID, save it so when cur ID catches up we have a response


offset_manager.go (1 line):
	- line 408: // TODO close the whole consumer for instance fenced....


client.go (1 line):
	- line 261: // FIXME: this InitProducerID seems to only be called from client_test.go (TestInitProducerIDConnectionRefused) and has been superceded by transaction_manager.go?