public void addToIndependentRuntimeItrMapForIndexCreation(CompiledIteratorDef itrDef)
      throws TypeMismatchException, NameResolutionException {

    Set<RuntimeIterator> set = new HashSet<>();
    computeUltimateDependencies(itrDef, set);
    // If the set is empty then add the self RuntimeIterator to the Map.
    if (set.isEmpty()) {
      RuntimeIterator itr = itrDef.getRuntimeIterator(this);
      set.add(itr);
    }
    itrDefToIndpndtRuntimeItrMap.put(itrDef, set);
  }
Populates the independent runtime iterator map for index creation purposes. This method does
not create any canonicalized index ids etc.
geode-core/src/main/java/org/apache/geode/cache/query/internal/ExecutionContext.java