@Override
    public void registerProcessor(byte protocolCode, CommandCode cmd, RemotingProcessor<?> processor) {
        ProtocolManager.getProtocol(ProtocolCode.fromBytes(protocolCode)).getCommandHandler()
            .registerProcessor(cmd, processor);
    }
@see RemotingServer#registerProcessor(byte, com.alipay.remoting.CommandCode, com.alipay.remoting.RemotingProcessor)
src/main/java/com/alipay/remoting/rpc/RpcServer.java