code: def __init__(self, mean, std=None):
      if std is None:
          assert len(mean) > 0
      else:
          assert len(mean) == len(std)
      self.mean = mean
      self.std = std
  
imports: import random
  import math
  import numpy
  import numbers
  import collections
  import cv2
  import torch
  import time
label_desc: Use image node_id 1 to create a new Normalize object from inherited base classes: object with example: obj = Normalize(mean, std)