presto-main/src/main/java/io/prestosql/sql/planner/plan/StatisticAggregationsDescriptor.java/StatisticAggregationsDescriptor/toString
class StatisticAggregationsDescriptor:    @Override
    public String toString()
    {
        return toStringHelper(this)
                .add("grouping", grouping)
                .add("tableStatistics", tableStatistics)
                .add("columnStatistics", columnStatistics)
                .toString();
    }