public boolean
equals(final Object arg) {
	return super.equals(arg) && ttl == ((OPTRecord) arg).ttl;
}
Determines if two OPTRecords are identical.  This compares the name, type,
class, and rdata (with names canonicalized).  Additionally, because TTLs
are relevant for OPT records, the TTLs are compared.
@param arg The record to compare to
@return true if the records are equal, false otherwise.
src/main/java/core/org/xbill/DNS/OPTRecord.java