@Override
    public NioTunnel getTunnel() {
        return null;
    }
UDP protocol virtual gateway tunnel wraps {@link UdpRemoteTunnel} and itself as client and
server.

@author Megatron King
@since 2018-11-25 20:16
netbare-core/src/main/java/com/github/megatronking/netbare/tunnel/UdpVATunnel.java