private void mute(KafkaChannel channel) {
        channel.mute();
        explicitlyMutedChannels.add(channel);
        keysWithBufferedRead.remove(channel.selectionKey());
    }
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