code: public synchronized EvernoteBusinessNotebookHelper getBusinessNotebookHelper() throws TException, EDAMUserException, EDAMSystemException {
          if (mBusinessNotebookHelper == null || isBusinessAuthExpired()) {
              mBusinessNotebookHelper = createBusinessNotebookHelper();
          }
          return mBusinessNotebookHelper;
      }
docs: Returns an async wrapper providing several helper methods for business notebooks. With
  {@link EvernoteBusinessNotebookHelper#getClient()} you can get access to the underlying {@link EvernoteNoteStoreClient},
  which references the business note store URL.
  
  @return An async wrapper providing several helper methods.