The ProtocolEncoder is responsible for writing the protocol and once the protocol
has been written, the ProtocolEncoder is replaced by the appropriate handler.
The ProtocolEncoder and the 'client' side of a member connection, will always
write the cluster protocol immediately. The ProtocolEncoder on the 'server' side
of the connection will wait till it has received the protocol and then will only
send the protocol if the client side was a member.
Fields inherited from class com.hazelcast.internal.networking.ChannelHandler