code: public Observable<List<PacketCaptureResultInner>> listAsync(String resourceGroupName, String networkWatcherName) {
          return listWithServiceResponseAsync(resourceGroupName, networkWatcherName).map(new Func1<ServiceResponse<List<PacketCaptureResultInner>>, List<PacketCaptureResultInner>>() {
              @Override
              public List<PacketCaptureResultInner> call(ServiceResponse<List<PacketCaptureResultInner>> response) {
                  return response.body();
              }
          });
      }
docs: Lists all packet capture sessions within the specified resource group.
  
  @param resourceGroupName The name of the resource group.
  @param networkWatcherName The name of the Network Watcher resource.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the List&lt;PacketCaptureResultInner&gt; object