code: public Observable<Page<EventHubConsumerGroupInfoInner>> listEventHubConsumerGroupsAsync(final String resourceGroupName, final String resourceName, final String eventHubEndpointName) {
          return listEventHubConsumerGroupsWithServiceResponseAsync(resourceGroupName, resourceName, eventHubEndpointName)
              .map(new Func1<ServiceResponse<Page<EventHubConsumerGroupInfoInner>>, Page<EventHubConsumerGroupInfoInner>>() {
                  @Override
                  public Page<EventHubConsumerGroupInfoInner> call(ServiceResponse<Page<EventHubConsumerGroupInfoInner>> response) {
                      return response.body();
                  }
              });
      }
docs: Get a list of the consumer groups in the Event Hub-compatible device-to-cloud endpoint in an IoT hub.
  Get a list of the consumer groups in the Event Hub-compatible device-to-cloud endpoint in an IoT hub.
  
  @param resourceGroupName The name of the resource group that contains the IoT hub.
  @param resourceName The name of the IoT hub.
  @param eventHubEndpointName The name of the Event Hub-compatible endpoint.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PagedList&lt;EventHubConsumerGroupInfoInner&gt; object