code: def test_len(self):
      size = 4
      dataset = tf.data.Dataset.from_tensor_slices(
          [[0, 1], [1, 1], [0, 0], [1, 0]]
      )
      data = ds.Dataset(dataset, size)
      self.assertLen(data, size)
  
file_path: mediapipe/mediapipe/model_maker/python/core/data/dataset_test.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import numpy
  import tensorflow
  from mediapipe.model_maker.python.core.data import dataset
  from mediapipe.model_maker.python.core.utils import test_util
label_desc: Use image node_id 2 for calling the DatasetTest obj's underlying member method code with example usage: obj.test_len() without return types