static Set getKeysToBeRemoved(Object o) {
    if (o instanceof NotEqualConditionEvaluator) {
      if (((NotEqualConditionEvaluator) o).notEqualTypeKeys == null) {
        return null;
      }
      return Collections.unmodifiableSet(((NotEqualConditionEvaluator) o).notEqualTypeKeys);
    } else {
      throw new IllegalStateException(
          "The Object is not of type NotEqualConditionEvaluator");
    }
  }
Test function which retrieves the "NOT EQUAL KEYS"

@param o Object of type NotEqualConditionEvaluator from which the set containing the keys for
       removal need to be retrieved
@return Unmodifiable Set containing the keys for removal
geode-core/src/main/java/org/apache/geode/cache/query/internal/RangeJunction.java