public void
present(Name name, int type, String record) throws IOException {
	newPrereq(Record.fromString(name, type, dclass, 0, record, origin));
}
Parses a record from the string, and inserts a prerequisite that the
record exists.  Due to the way value-dependent prequisites work, the
condition that must be met is that the set of all records with the same 
and type in the update message must be identical to the set of all records
with that name and type on the server.
@throws IOException The record could not be parsed.
src/main/java/core/org/xbill/DNS/Update.java