code: public final Set<Type> getTypeClosure(BaseTypeFactory typeFactory)
    {
      if (_typeSet == null) {
        LinkedHashSet<Type> typeSet = new LinkedHashSet<Type>();
        
        fillTypeClosure(typeFactory, typeSet);
        
        _typeSet = typeSet;
      }
      
      return _typeSet;
    }
docs: Returns the type closure of the base type.