void
rrFromWire(DNSInput in) throws IOException {
	preference = in.readU16();
	map822 = new Name(in);
	mapX400 = new Name(in);
}
Creates an PX Record from the given data
@param preference The preference of this mail address.
@param map822 The RFC 822 component of the mail address.
@param mapX400 The X.400 component of the mail address.
src/main/java/core/org/xbill/DNS/PXRecord.java