code: public static TokenResponse token(Map<String, Object> params, RequestOptions options)
        throws StripeException {
      String url = Stripe.getConnectBase() + "/oauth/token";
      return OAuth.stripeResponseGetter.oauthRequest(ApiResource.RequestMethod.POST, url, params,
          TokenResponse.class, ApiResource.RequestType.NORMAL, options);
    }
docs: Uses an authorization code to connect an account to your platform and
  fetch the user's credentials.
  
  @param params  the request parameters.
  @param options the request options.
  @return the TokenResponse instance containing the response from the OAuth
  API.