code: def _init():
      r"""Register prims as implementation of var_mean and group_norm."""
      global _lib
      if is_built() is False or _lib is not None:
          return
      from ..._decomp.decompositions import (
          native_group_norm_backward as _native_group_norm_backward,
      )
      from ..._refs import (
          native_group_norm as _native_group_norm,
          var_mean as _var_mean,
      )
  
      _lib = _Library("aten", "IMPL")
      _lib.impl("var_mean.correction", _var_mean, "MPS")
      _lib.impl("native_group_norm", _native_group_norm, "MPS")
      _lib.impl(
          "native_group_norm_backward",
          _native_group_norm_backward,
          "MPS",
      )
  
file_path: pytorch/torch/backends/mps/__init__.py
imports: from functools import lru_cache
  import torch
  from ...library import Library
label_desc: Use image node_id 5 for calling a global function with example usage: _init() without return types