code: def create_block(config, layer_idx=None):
      last_layer_subset = getattr(config, "last_layer_subset", False)
      cross_attn = (
          last_layer_subset
          and layer_idx == config.num_hidden_layers - 1
      )
      # TD [2022-12-19]: For cross attention (last layer), we actually want to return the
      # residual x_kv, not residual x. But it's annoying to change the API (and it only affects
      # one layer) so we just choose not to return residual in this case.
      return_residual = not cross_attn
      mixer_cls = create_mixer_cls(
          config, cross_attn, return_residual=return_residual
      )
      mlp_cls = create_mlp_cls(
          config, layer_idx, return_residual=return_residual
      )
      norm_cls = partial(nn.LayerNorm, eps=config.layer_norm_eps)
      block = Block(
          config.hidden_size,
          mixer_cls,
          mlp_cls,
          norm_cls=norm_cls,
          prenorm=False,
          resid_dropout1=config.hidden_dropout_prob,
          resid_dropout2=config.hidden_dropout_prob,
          fused_dropout_add_ln=getattr(
              config, "fused_dropout_add_ln", False
          ),
          return_residual=return_residual,
      )
      return block
  
imports: import logging
  import re
  from collections import OrderedDict
  from collections.abc import Sequence
  from functools import partial
  from typing import Any, Mapping
  import torch
  import torch.nn
  import torch.nn.functional
  from einops import rearrange
  from transformers import BertConfig, PretrainedConfig
  from transformers.models.bert.modeling_bert import BaseModelOutputWithPoolingAndCrossAttentions, BertForPreTrainingOutput
  from flash_attn.bert_padding import index_first_axis, index_first_axis_residual, pad_input, unpad_input
  from flash_attn.modules.block import Block
  from flash_attn.modules.embedding import BertEmbeddings
  from flash_attn.modules.mha import MHA
  from flash_attn.modules.mlp import FusedMLP, Mlp
  from flash_attn.utils.pretrained import state_dict_from_pretrained
label_desc: Use image node_id 3 for calling a global function with example usage: create_block(config, layer_idx) and returns: block