docs: public final void copySubcatalogsGs(
      final TradingCatalog pCatalog,
        final List<CatalogGs> pCatalogsGs) {
      for (TradingCatalog cat : pCatalog.getSubcatalogs()) {
        pCatalogsGs.add(cat.getCatalog());
        for (TradingCatalog cati : cat.getSubcatalogs()) {
          pCatalogsGs.add(cati.getCatalog());
          //recursion:
          copySubcatalogsGs(cati, pCatalogsGs);
        }
      }
    }