code: def _replace_module(model, policies, layer_id=0):
      """Traverse model's children recursively and apply any transformations in ``policies``.
      Arguments:
          model (torch.nn.Module): model to augment
          policies (dict): Mapping of source class to replacement function.
      Returns:
          Modified ``model``.
      """
      for name, child in model.named_children():
          if child.__class__ in policies:
              replaced_module = policies[child.__class__][0](
                  child, policies[child.__class__][-1], layer_id
              )
              setattr(model, name, replaced_module)
              if isinstance(model, PipelineModule):
                  assert hasattr(
                      model, "forward_funcs"
                  ), "we require pipe-module to have the list of fwd_functions"
                  model.forward_funcs[
                      model.fwd_map[name]
                  ] = replaced_module
              layer_id += 1
          else:
              _, layer_id = _replace_module(
                  child, policies, layer_id=layer_id
              )
  
      return model, layer_id
  
imports: import os
  import torch
  import tqdm
  import deepspeed
  import deepspeed.ops.transformer
  from deepspeed.ops.transformer.inference.diffusers_attention import DeepSpeedDiffusersAttention
  from deepspeed.ops.transformer.inference.diffusers_transformer_block import DeepSpeedDiffusersTransformerBlock
  from deepspeed.ops.transformer.inference.diffusers_2d_transformer import Diffusers2DTransformerConfig
  from .replace_policy import HFBertLayerPolicy, HFGPT2LayerPolicy, BLOOMLayerPolicy
  from .replace_policy import replace_policies, generic_policies
  from deepspeed import comm
  from torch import nn
  from ..runtime.zero import GatheredParameters
  from .layers import LinearAllreduce, LinearLayer
  from .load_checkpoint import load_model_with_checkpoint
  import time
  from ..pipe import PipelineModule
label_desc: Use image node_id 7 for calling a global function with example usage: _replace_module(model, policies, layer_id) and returns: model,  layer_id