class_docstr: Produces a sequence of MNIST digits with labels.
code: def __len__(self):
      return int(tf.math.ceil(len(self.images) / self.batch_size))
  
imports: import os
  import warnings
  from absl import app
  from absl import flags
  import matplotlib
  from matplotlib import figure
  from matplotlib.backends import backend_agg
  import numpy
  import tensorflow.compat.v2
  import tensorflow_probability
  from tensorflow_probability.python.internal import tf_keras
label_desc: Use image node_id 4 for calling the MNISTSequence obj's underlying member method code with example usage: obj.__len__() and returns: int