docs: @Override
      public Categories getCategories(final AtomRequest areq) throws AtomException {
          LOG.debug("getCollection");
          final String[] pathInfo = StringUtils.split(areq.getPathInfo(), "/");
          final String handle = pathInfo[0];
          final String collection = pathInfo[1];
          final FileBasedCollection col = service.findCollectionByHandle(handle, collection);
          return col.getCategories(true).get(0);
      }