code: public AlluxioURI join(String suffix) {
      // TODO(gpang): there should be other usage of join() which can use joinUnsafe() instead.
      String path = getPath();
      StringBuilder sb = new StringBuilder(path.length() + 1 + suffix.length());
  
      return new AlluxioURI(this,
          sb.append(path).append(AlluxioURI.SEPARATOR).append(suffix).toString(), true);
    }
docs: Append additional path elements to the end of an {@link AlluxioURI}.
  
  @param suffix the suffix to add
  @return the new {@link AlluxioURI}