code: def test_tile_images(self):
      B = np.random.randint(10, 20)
      n_col = np.random.randint(2, 5)
      H = 30
      W = 40
  
      imgs = np.random.uniform(255, size=(B, 3, H, W))
      tile = tile_images(imgs, n_col, self.pad, fill=self.fill)
  
      if isinstance(self.pad, int):
          pad_y = self.pad
          pad_x = self.pad
      else:
          pad_y, pad_x = self.pad
      n_row = int(math.ceil(B / n_col))
      self.assertTrue(n_col >= 1 and n_row >= 1)
      start_y_11 = H + pad_y + pad_y // 2
      start_x_11 = W + pad_x + pad_x // 2
      tile_11 = tile[
          :, start_y_11 : start_y_11 + H, start_x_11 : start_x_11 + W
      ]
  
      np.testing.assert_equal(tile_11, imgs[(n_col - 1) + 2])
  
file_path: chainercv/tests/utils_tests/image_tests/test_tile_images.py
imports: from __future__ import division
  import math
  import numpy
  import unittest
  from chainercv.utils import testing
  from chainercv.utils import tile_images
label_desc: Use image node_id 1 for calling the TestTileImages obj's underlying member method code with example usage: obj.test_tile_images() without return types