code: def base64_to_cv2(b64str: str):
      """
      Convert data from base64 to BGR format.
      """
      data = base64.b64decode(b64str.encode("utf8"))
      data = np.fromstring(data, np.uint8)
      data = cv2.imdecode(data, cv2.IMREAD_COLOR)
      return data
  
imports: import random
  import base64
  from typing import Callable, Union, List, Tuple
  import cv2
  import numpy
  import paddle
  import paddle.nn.functional
  from paddleseg.transforms import functional
  from PIL import Image
label_desc: Use image node_id 4 for calling a global function with example usage: base64_to_cv2(b64str) and returns: data