code: def test_invalid_block_size():
      image = np.arange(4 * 6).reshape(4, 6)
  
      with testing.raises(ValueError):
          block_reduce(image, [1, 2, 3])
      with testing.raises(ValueError):
          block_reduce(image, [1, 0.5])
  
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 6 for calling a global function with example usage: test_invalid_block_size() without return types