@Override
  @SuppressWarnings("unchecked")
  public Region<K, V> createSubregion(Region<?, ?> parent, String name)
      throws RegionExistsException {
    if (internalRegionArguments == null) {
      return super.createSubregion(parent, name);
    }
    try {
      return ((InternalRegion) parent).createSubregion(name, getRegionAttributes(),
          internalRegionArguments);
    } catch (IOException | ClassNotFoundException e) {
      throw new InternalGemFireError("unexpected exception", e);
    }
  }
Returns the region attributes that would currently be used to create the region.
geode-core/src/main/java/org/apache/geode/internal/cache/InternalRegionFactory.java