code: def test_square_ratio_with_default_mode_and_cval(self):
      heatmaps = self.heatmaps
      heatmaps_padded = heatmaps.pad_to_aspect_ratio(1.0)
      assert heatmaps_padded.arr_0to1.shape == (3, 3, 1)
      assert np.allclose(
          heatmaps_padded.arr_0to1[:, :, 0],
          np.float32(
              [[0.0, 0.0, 1.0], [0.0, 0.0, 1.0], [0.0, 0.0, 0.0]]
          ),
      )
  
imports: from __future__ import print_function, division, absolute_import
  import sys
  import numpy
  import six.moves
  import imgaug
label_desc: Use image node_id 2 for calling the TestHeatmapsOnImage_pad_to_aspect_ratio obj's underlying member method code with example usage: obj.test_square_ratio_with_default_mode_and_cval() without return types