@Override
  public int getSizeEstimate(ExecutionContext context) {
    return 1;
  }
This structure contains the filter evaluable and iter evaluable conditions which are dependent on
a group of iterators derived from a single independent iterator ( an iterator on the region) .
The iter evaluatable conditions belonging to other group of iterators can be a part of
GroupJunction only if the complete expansion flag is true.
geode-core/src/main/java/org/apache/geode/cache/query/internal/GroupJunction.java