code: public String buildOAuthUrl(ConnectionFactory<?> connectionFactory, NativeWebRequest request) {
  		return buildOAuthUrl(connectionFactory, request, null);
  	}
docs: Builds the provider URL to redirect the user to for connection authorization.
  @param connectionFactory the service provider's connection factory e.g. FacebookConnectionFactory
  @param request the current web request
  @return the URL to redirect the user to for authorization
  @throws IllegalArgumentException if the connection factory is not OAuth1 based.