Record
getObject() {
	return new SIGRecord();
}
Signature - A SIG provides the digital signature of an RRset, so that
the data can be authenticated by a DNSSEC-capable resolver.  The
signature is usually generated by a key contained in a KEYRecord
@see RRset
@see DNSSEC
@see KEYRecord

@author Brian Wellington
src/main/java/core/org/xbill/DNS/SIGRecord.java