public void
setEDNS(int level, int payloadSize, int flags, List options) {
	if (level != 0 && level != -1)
		throw new IllegalArgumentException("invalid EDNS level - " +
						   "must be 0 or -1");
	if (payloadSize == 0)
		payloadSize = DEFAULT_EDNS_PAYLOADSIZE;
	queryOPT = new OPTRecord(payloadSize, 0, level, flags, options);
}
Sets the local address to bind to when sending messages.  A random port
will be used.
@param addr The local address to send messages from.
src/main/java/core/org/xbill/DNS/SimpleResolver.java