code: def pad(x, max_length):
      bs, n = x.shape
      if n < max_length:
          padding = torch.zeros(bs, max_length - n, dtype=x.dtype)
          x = torch.cat([x, padding], dim=1)
      return x
  
imports: import os
  import torch
  import torch.nn.functional
  from typing import Any, List, Dict
  from collections import OrderedDict
  from torch import nn
  from towhee.models.mdmmt.bert_mmt import BertMMT
label_desc: Use image node_id 2 for calling a global function with example usage: pad(x, max_length) and returns: x