presto-orc/src/main/java/io/prestosql/orc/metadata/statistics/StringStatisticsBuilder.java/StringStatisticsBuilder/addValue
class StringStatisticsBuilder:    @Override
    public void addValue(Slice value)
    {
        requireNonNull(value, "value is null");

        if (nonNullValueCount == 0) {
            checkState(minimum == null && maximum == null);
            minimum = value;
            maximum = value;
        }
        else if (minimum != null && value.compareTo(minimum) <= 0) {
            minimum = value;
        }
        else if (maximum != null && value.compareTo(maximum) >= 0) {
            maximum = value;
        }

        nonNullValueCount++;
        sum = addExact(sum, value.length());
    }