code: public StylesheetComposed getStylesheetComposed()
    {
  
      Stylesheet sheet = this;
  
      while (!sheet.isAggregatedType())
      {
        sheet = sheet.getStylesheetParent();
      }
  
      return (StylesheetComposed) sheet;
    }
docs: Get the owning aggregated stylesheet, or this
  stylesheet if it is aggregated.
  
  @return the owning aggregated stylesheet or itself