code: public Observable<Page<DataBoxEdgeDeviceInner>> listAsync(final String expand) {
          return listWithServiceResponseAsync(expand)
              .map(new Func1<ServiceResponse<Page<DataBoxEdgeDeviceInner>>, Page<DataBoxEdgeDeviceInner>>() {
                  @Override
                  public Page<DataBoxEdgeDeviceInner> call(ServiceResponse<Page<DataBoxEdgeDeviceInner>> response) {
                      return response.body();
                  }
              });
      }
docs: Gets all the data box edge/gateway devices in a subscription.
  
  @param expand Specify $expand=details to populate additional fields related to the resource or Specify $skipToken=&lt;token&gt; to populate the next page in the list.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PagedList&lt;DataBoxEdgeDeviceInner&gt; object