code: def _create_random(length) -> str:
      ALPHABET = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
      chars = []
      for i in range(length):
          chars.append(random.choice(ALPHABET))
      key = "".join(chars)
      key_bytes = key.encode("ascii")
      base64_str = base64.b64encode(key_bytes)
      print(len(base64_str), flush=True)
      return base64_str
  
imports: import torch.nn.functional
  import torch, os, io
  import base64
  import torch.nn
  import unittest
  import random
  from bigdl.nano.pytorch.patching import patch_encryption
  import torch.optim
label_desc: Use image node_id 1 for calling a global function with example usage: _create_random(length) and returns: base64_str