def METHOD_NAME(self):
    arr = np.ones((20, 20, 4), dtype=np.uint8)
    da = DataArray(arr, dims=['x', 'y', 'band'])
    rs = XarraySource(da, IdentityCRSTransformer())
    chips = list(random_chip_stream([rs], chip_sz=100, sample_prob=0.5))
    self.assertEqual(len(chips), 1)
    self.assertEqual(chips[0].shape, (20, 20, 4))