public String getSingleSplit(String value, List<Pair<Integer, Integer>> splitList, int split) {
        Pair<Integer, Integer> splitRange = splitList.get(split);
        if (splitRange == null) {
            return null;
        }
        return value.substring(splitRange.getLeft(), splitRange.getRight());
    }
Find the start offset of split

@param chars The input in which we are seeking
@param split  The split number for which we are looking for the start
@return The offset or -1 if it does not exist
analyzer/src/main/java/nl/basjes/parse/useragent/utils/Splitter.java