docs: public static synchronized CatalogResolver getCatalogResolver() {
          if (catalogResolver == null) {
              final CatalogManager manager = new CatalogManager();
              manager.setIgnoreMissingProperties(true);
              manager.setUseStaticCatalog(false); // We'll use a private catalog.
              manager.setPreferPublic(true);
              final File catalogFilePath = new File(ditaDir, Configuration.pluginResourceDirs.get("org.dita.base") + File.separator + FILE_NAME_CATALOG);
              manager.setCatalogFiles(catalogFilePath.toURI().toASCIIString());
              //manager.setVerbosity(10);
              catalogResolver = new CatalogResolver(manager);
          }
  
          return catalogResolver;
      }