code: public Flux<ConfigurationSetting> listSettingRevisions(SettingSelector selector) {
          Mono<PagedResponse<ConfigurationSetting>> result;
          if (selector != null) {
              String fields = getSelectQuery(selector.fields());
              result = service.listKeyValueRevisions(serviceEndpoint, selector.key(), selector.label(), fields, selector.acceptDateTime(), null);
          } else {
              result = service.listKeyValueRevisions(serviceEndpoint, null, null, null, null, null);
          }
  
          return result.flatMapMany(this::extractAndFetchConfigurationSettings);
      }
docs: Lists chronological/historical representation of {@link ConfigurationSetting} resource(s). Revisions are provided
  in descending order from their {@link ConfigurationSetting#lastModified() lastModified} date. Revisions expire
  after a period of time. The service maintains change history for up to 7 days.
  
  If {@code options} is {@code null}, then all the {@link ConfigurationSetting ConfigurationSettings} are fetched
  in their current state. Otherwise, the results returned match the parameters given in {@code options}.
  
  @param selector Optional. Used to filter configuration setting revisions from the service.
  @return Revisions of the ConfigurationSetting