presto-parquet/src/main/java/io/prestosql/parquet/reader/PrimitiveColumnReader.java/PrimitiveColumnReader/updateValueCounts
class PrimitiveColumnReader:    private void updateValueCounts(int valuesRead)
    {
        if (valuesRead == remainingValueCountInPage) {
            page = null;
            valuesReader = null;
        }
        remainingValueCountInPage -= valuesRead;
        currentValueCount += valuesRead;
    }