code: def __len__(self):
      return len(self.array)
  
imports: from __future__ import division, print_function, absolute_import
  import os
  import random
  import numpy
  from PIL import Image
  import pickle
  import csv
  import warnings
  import tensorflow.compat.v1
  from io import BytesIO
label_desc: Use image node_id 3 for calling the Preloader obj's underlying member method code with example usage: obj.__len__() and returns: len