code: @Override
      public void stage2NamespaceCompilation(final Document doc)
              throws ResourceDownloadError, IndexingFailure {
          for (Namespace ns : doc.getAllNamespaces()) {
              String resourceLocation = ns.getResourceLocation();
  
              if (!namespace.isOpen(resourceLocation)) {
                  namespace.compileNamespace(resourceLocation);
              }
          }
      }
docs: {@inheritDoc}