code: def _get_check(self, ds):
      image_formats = (
          (4, 300, 300),
          (1, 300, 300),
          (4, 285, 1000),
          (3, 404, 1417),
          (4, 404, 1417),
      )
      for i in range(5):
          fmt = image_formats[i]
          img = ds.get_example(i)
          self.assertEqual(img.dtype, self.dtype)
          self.assertEqual(img.shape, fmt)
  
imports: import os
  import pickle
  import unittest
  import numpy
  from chainer import datasets
  from chainer.datasets import image_dataset
  from chainer import testing
label_desc: Use image node_id 3 for calling the TestMultiZippedImageDataset obj's underlying member method code with example usage: obj._get_check(ds) without return types