code: public static QuandlSession create() {
      try {
        String authToken = System.getProperty(GenericQuandlSession.QUANDL_AUTH_TOKEN_PROPERTY_NAME);
        if (authToken != null) {
          return new QuandlSession(SessionOptions.Builder.withAuthToken(authToken).build());
        }
      } catch (SecurityException se) {
        s_logger.debug("Error accessing system property " + GenericQuandlSession.QUANDL_AUTH_TOKEN_PROPERTY_NAME + ", falling back to not using an auth token",
            se);
      }
      return new QuandlSession(SessionOptions.Builder.withoutAuthToken().build());
    }
docs: Create a Quandl session without an authorization token (authToken). An attempt will be made to read the java property
  <em>quandl.auth.token</em> and use that if available. Any resulting SecurityException is logged at debug level, otherwise it is ignored
  and no auth token is used. Using a token means you can make more requests. Note creating this object does not make any actual API
  requests, the token is used in subsequent requests.
  
  @return an instance of the Quandl session, not null.