code: def instance_nvfuser_factory(dim):
      """
      `InstanceNorm3dNVFuser` is a faster version of InstanceNorm layer and implemented in `apex`.
      It only supports 3d tensors as the input. It also requires to use with CUDA and non-Windows OS.
      In this function, if the required library `apex.normalization.InstanceNorm3dNVFuser` does not exist,
      `nn.InstanceNorm3d` will be returned instead.
      This layer is based on a customized autograd function, which is not supported in TorchScript currently.
      Please switch to use `nn.InstanceNorm3d` if TorchScript is necessary.
  
      Please check the following link for more details about how to install `apex`:
      https://github.com/NVIDIA/apex#installation
  
      """
  
      if dim != 3:
          types = (nn.InstanceNorm1d, nn.InstanceNorm2d)
          warnings.warn(
              f"`InstanceNorm3dNVFuser` only supports 3d cases, use {types[dim - 1]} instead."
          )
          return types[dim - 1]
  
      if not has_nvfuser_instance_norm():
          warnings.warn(
              "`apex.normalization.InstanceNorm3dNVFuser` is not installed properly, use nn.InstanceNorm3d instead."
          )
          return nn.InstanceNorm3d
      return optional_import(
          "apex.normalization", name="InstanceNorm3dNVFuser"
      )[0]
  
imports: from __future__ import annotations
  import warnings
  from collections.abc import Callable
  from typing import Any
  import torch.nn
  from monai.networks.utils import has_nvfuser_instance_norm
  from monai.utils import ComponentStore, look_up_option, optional_import
label_desc: Use image node_id 5 for calling a global function with example usage: instance_nvfuser_factory(dim) and returns: optional_import, types, nn