presto-main/src/main/java/io/prestosql/operator/StatisticsWriterOperator.java/StatisticsWriterOperator/StatisticsWriterOperator
class StatisticsWriterOperator:    public StatisticsWriterOperator(OperatorContext operatorContext, StatisticsWriter statisticsWriter, StatisticAggregationsDescriptor<Integer> descriptor, boolean rowCountEnabled)
    {
        this.operatorContext = requireNonNull(operatorContext, "operatorContext is null");
        this.statisticsWriter = requireNonNull(statisticsWriter, "statisticsWriter is null");
        this.descriptor = requireNonNull(descriptor, "descriptor is null");
        this.rowCountEnabled = rowCountEnabled;
    }