code: public static QuandlSession create(final String authToken) {
      ArgumentChecker.notNull(authToken, "authToken");
      return new QuandlSession(SessionOptions.Builder.withAuthToken(authToken).build());
    }
docs: Create a Quandl session to use a specific authorization token (authToken) with all requests. Using a token means you can make more
  requests. Note that this method does not check the quandl.auth.token property. Creating this object does not make any actual API
  requests, the token is used in subsequent requests.
  
  @param authToken a Quandl API authorization token
  @return an instance of the Quandl session with an embedded authorization token