code: public Observable<LogsInner> listAsync(String resourceGroupName, String containerGroupName, String containerName, Integer tail) {
          return listWithServiceResponseAsync(resourceGroupName, containerGroupName, containerName, tail).map(new Func1<ServiceResponse<LogsInner>, LogsInner>() {
              @Override
              public LogsInner call(ServiceResponse<LogsInner> response) {
                  return response.body();
              }
          });
      }
docs: Get the logs for a specified container instance.
  Get the logs for a specified container instance in a specified resource group and container group.
  
  @param resourceGroupName The name of the resource group.
  @param containerGroupName The name of the container group.
  @param containerName The name of the container instance.
  @param tail The number of lines to show from the tail of the container instance log. If not provided, all available logs are shown up to 4mb.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the LogsInner object