code: public static void registerInputStreamHandler(MimeType type, InputStreamHandler handler) {
          $.requireNotNull(handler);
          InputStreamHandlerDispatcher dispatcher = inputStreamHandlerLookup.get(type);
          if (null == dispatcher) {
              dispatcher = new InputStreamHandlerDispatcher(handler);
              inputStreamHandlerLookup.put(type, dispatcher);
          } else {
              dispatcher.add(handler);
          }
      }
docs: Associate an {@link InputStreamHandler} with a specific {@link MimeType}
  @param type
  The mimetype the handler listen to
  @param handler
  the handler