code: public EvernoteHtmlHelper getLinkedHtmlHelper(@NonNull LinkedNotebook linkedNotebook) throws EDAMUserException, EDAMSystemException, EDAMNotFoundException, TException {
          String key = linkedNotebook.getGuid();
  
          EvernoteHtmlHelper htmlHelper = mLinkedHtmlHelper.get(key);
          if (htmlHelper == null) {
              String url = linkedNotebook.getNoteStoreUrl();
  
              EvernoteNoteStoreClient client = getNoteStoreClient(url, EvernotePreconditions.checkNotEmpty(mEvernoteSession.getAuthToken()));
              AuthenticationResult authenticationResult = client.authenticateToSharedNotebook(linkedNotebook.getShareKey());
  
              htmlHelper = createHtmlHelper(authenticationResult.getAuthenticationToken());
  
              mLinkedHtmlHelper.put(key, htmlHelper);
          }
  
          return htmlHelper;
      }
docs: Use this method, if you want to download a linked note as HTML.
  
  @param linkedNotebook The referenced {@link LinkedNotebook}. Its GUID and share key must not be
  {@code null}.
  @return An async wrapper to load a note as HTML from the Evernote service.