docs: public static Pair<InMemoryJarfile, String> loadAndUpgradeCatalogFromJar(InMemoryJarfile jarfile, boolean isXDCR)
          throws IOException
      {
          // Let VoltCompiler do a version check and upgrade the catalog on the fly.
          // I.e. jarfile may be modified.
          VoltCompiler compiler = new VoltCompiler(isXDCR);
          String upgradedFromVersion = compiler.upgradeCatalogAsNeeded(jarfile);
          return new Pair<>(jarfile, upgradedFromVersion);
      }