@Override
    public MemoryIndexStoreEntry next() {
      if (valuesIterator == null) {
        currentEntry.setMemoryIndexStoreEntry(currKey, (RegionEntry) currValue);
        return currentEntry;
      }

      RegionEntry re = (RegionEntry) valuesIterator.next();
      if (re == null) {
        throw new NoSuchElementException();
      }

      currentEntry.setMemoryIndexStoreEntry(currKey, re);
      return currentEntry;
    }
returns a new InMemoryIndexStorageEntry with current index key and its next value which is
the next RE in the collection. Make sure hasNext() has been called before calling this method
geode-core/src/main/java/org/apache/geode/cache/query/internal/index/MemoryIndexStore.java