Any]], Iterable[torch.nn.Parameter]]]*)
           -- Input passed into the optimizer "optim" representing
           either a "list" of parameter groups or an iterable of
           parameters; if "None", then this method assumes the input
           was "model.parameters()". This argument is deprecated, and
           there is no need to pass it in anymore. (Default: "None")
     * **rank0_only** (*bool*) -- If "True", saves the populated
       "dict" only on rank 0; if "False", saves it on all ranks.
       (Default: "True")

     * **group** (*dist.ProcessGroup*) -- Model's process group or
       "None" if using the default process group. (Default:
       "None")

  Returns:
     A "dict" containing the optimizer state for "model" 's
     original unflattened parameters and including keys "state"
     and "param_groups" following the convention of
     "torch.optim.Optimizer.state_dict()". If "rank0_only=True",
