location of output for single-device CUDA modules. For multi-
        device modules and CPU modules, it must be "None", and the
        module itself dictates the output location. (default:
        "device_ids[0]" for single-device modules)
  * **broadcast_buffers** (*bool*) -- Flag that enables syncing
    (broadcasting) buffers of the module at beginning of the
    "forward" function. (default: "True")

  * **process_group** -- The process group to be used for
    distributed data all-reduction. If "None", the default process
    group, which is created by
    "torch.distributed.init_process_group()", will be used.
    (default: "None")

  * **bucket_cap_mb** -- "DistributedDataParallel" will bucket
    parameters into multiple buckets so that gradient reduction of
    each bucket can potentially overlap with backward computation.
    "bucket_cap_mb" controls the bucket size in MegaBytes (MB).
    (default: 25)
