code: public String getAuthorizationUrl(Map<String, String> additionalParams) {
          return createAuthorizationUrlBuilder()
                  .additionalParams(additionalParams)
                  .build();
      }
docs: Returns the URL where you should redirect your users to authenticate your application.
  
  @param additionalParams any additional GET params to add to the URL
  @return the URL where you should redirect your users