public static ZoneTransferIn
newIXFR(Name zone, long serial, boolean fallback, SocketAddress address,
	TSIG key)
{
	return new ZoneTransferIn(zone, Type.IXFR, serial, fallback, address,
				  key);
}
Instantiates a ZoneTransferIn object to do an IXFR (incremental zone
transfer).
@param zone The zone to transfer.
@param serial The existing serial number.
@param fallback If true, fall back to AXFR if IXFR is not supported.
@param address The host/port from which to transfer the zone.
@param key The TSIG key used to authenticate the transfer, or null.
@return The ZoneTransferIn object.
src/main/java/core/org/xbill/DNS/ZoneTransferIn.java