retrieveRanges(context, range1, range2) {
        // process args
        range2 = Address.extend(range1, range2);

        // retrieve values
        range1 = this.retrieveArg(context, range1);
        range1 = H.accept(range1, Types.ARRAY, undefined, false, true);

        if (range2 !== range1) {
            range2 = this.retrieveArg(context, range2);
            range2 = H.accept(range2, Types.ARRAY, undefined, false, true);
        } else
            range2 = range1;

        return [range1, range2];
    }
Helper function for SUMIF, AVERAGEIF,...
@param context
@param range1
@param range2