code: def test_default_block_size():
      image = np.arange(4 * 6).reshape(4, 6)
      out = block_reduce(image, func=np.min)
      expected = np.array([[0, 2, 4], [12, 14, 16]])
      assert_equal(expected, out)
  
file_path: scikit-image/skimage/measure/tests/test_block.py
imports: import numpy
  from skimage.measure import block_reduce
  from skimage._shared import testing
  from skimage._shared.testing import assert_equal
label_desc: Use image node_id 7 for calling a global function with example usage: test_default_block_size() without return types