text: public static CFRecordsAggregate CreateCFAggregate(RecordStream rs){Record rec = rs.GetNext();if (rec.Sid != CFHeaderRecord.sid){throw new InvalidOperationException("next record sid was " + rec.Sid+ " instead of " + CFHeaderRecord.sid + " as expected");}CFHeaderRecord header = (CFHeaderRecord)rec;int nRules = header.NumberOfConditionalFormats;CFRuleRecord[] rules = new CFRuleRecord[nRules];for (int i = 0; i < rules.Length; i++){rules[i] = (CFRuleRecord)rs.GetNext();}return new CFRecordsAggregate(header, rules);}