code: public final List<AbstractTraceRegion> getNestedRegions() {
  		if (nestedRegions == null)
  			return Collections.emptyList();
  		return Collections.unmodifiableList(nestedRegions);
  	}
docs: Returns the nested trace regions. The list does not necessarily contain all the regions that will be returned by
  the {@link #leafIterator()}.
  
  @return the list of directly nested regions.