public Record
nextRecord() throws IOException {
	Record rec = null;
	try {
		rec = _nextRecord();
	}
	finally {
		if (rec == null) {
			st.close();
		}
	}
	return rec;
}
Returns the next record in the master file.  This will process any
directives before the next record.
@return The next record.
@throws IOException The master file could not be read, or was syntactically
invalid.
src/main/java/core/org/xbill/DNS/Master.java