code: protected String getFacebookGraphEndpointUrl() {
      if (apiVersion.isUrlElementRequired()) {
        return getFacebookEndpointUrls().getGraphEndpoint() + '/' + apiVersion.getUrlElement();
      } else {
        return getFacebookEndpointUrls().getGraphEndpoint();
      }
    }
docs: Returns the base endpoint URL for the Graph API.
  
  @return The base endpoint URL for the Graph API.