@Override
  public void accumulate(Object value) {
    if (value != null && value != QueryService.UNDEFINED) {
      distinct.add(value);
    }
  }
The class used to hold the distinct values. This will get instantiated on the bucket node as part
of distinct queries for sum, count, average.
geode-core/src/main/java/org/apache/geode/cache/query/internal/aggregate/DistinctAggregator.java