text: public int AddConditionalFormatting(CellRangeAddress[] regions, IConditionalFormattingRule[] cfRules){if (regions == null){throw new ArgumentException("regions must not be null");}if (cfRules == null){throw new ArgumentException("cfRules must not be null");}if (cfRules.Length == 0){throw new ArgumentException("cfRules must not be empty");}if (cfRules.Length > 3){throw new ArgumentException("Number of rules must not exceed 3");}CFRuleRecord[] rules = new CFRuleRecord[cfRules.Length];for (int i = 0; i != cfRules.Length; i++){rules[i] = ((HSSFConditionalFormattingRule)cfRules[i]).CfRuleRecord;}CFRecordsAggregate cfra = new CFRecordsAggregate(regions, rules);return _conditionalFormattingTable.Add(cfra);}