code: def check_non_maximum_suppression_zero_legnth_bbox(
      self, bbox, threshold
  ):
      selec = non_maximum_suppression(bbox, threshold)
      self.assertIsInstance(selec, type(bbox))
      self.assertEqual(selec.shape, (0,))
  
imports: import unittest
  import numpy
  from chainer.backends import cuda
  from chainer import testing
  from chainer.testing import attr
  from chainercv.utils import generate_random_bbox
  from chainercv.utils import non_maximum_suppression
label_desc: Use image node_id 2 for calling the TestNonMaximumSuppressionZeroLengthBbox obj's underlying member method code with example usage: obj.check_non_maximum_suppression_zero_legnth_bbox(bbox, threshold) without return types