private void unmute(KafkaChannel channel) {
        // Remove the channel from explicitlyMutedChannels only if the channel has been actually unmuted.
        if (channel.maybeUnmute()) {
            explicitlyMutedChannels.remove(channel);
            if (channel.hasBytesBuffered()) {
                keysWithBufferedRead.add(channel.selectionKey());
                madeReadProgressLastPoll = true;
            }
        }
    }
handle any ready I/O on a set of selection keys
@param selectionKeys set of keys to handle
@param isImmediatelyConnected true if running over a set of keys for just-connected sockets
@param currentTimeNanos time at which set of keys was determined
clients/src/main/java/org/apache/kafka/common/network/Selector.java