}
private void addListener(Channel channel) {
if (channel instanceof PublisherCallbackChannel) {
PublisherCallbackChannel publisherCallbackChannel = (PublisherCallbackChannel) channel;
SortedMap<Long, PendingConfirm> pendingConfirms = publisherCallbackChannel.addListener(this);
Channel key = channel instanceof ChannelProxy ? ((ChannelProxy) channel).getTargetChannel() : channel;
if (this.pendingConfirms.putIfAbsent(key, pendingConfirms) == null
&& logger.isDebugEnabled()) {
logger.debug("Added pending confirms for " + channel + " to map, size now " + this.pendingConfirms.size());
}