code: def check(self, mask, expected):
      bbox = mask_to_bbox(mask)
  
      self.assertIsInstance(bbox, type(expected))
      self.assertEqual(bbox.dtype, expected.dtype)
      np.testing.assert_equal(cuda.to_cpu(bbox), cuda.to_cpu(expected))
  
file_path: chainercv/tests/utils_tests/mask_tests/test_mask_to_bbox.py
imports: from __future__ import division
  import unittest
  import numpy
  from chainer.backends import cuda
  from chainer import testing
  from chainer.testing import attr
  from chainercv.utils import mask_to_bbox
label_desc: Use image node_id 1 for calling the TestMaskToBbox obj's underlying member method code with example usage: obj.check(mask, expected) without return types