code: def test_empty_line():
      coords = line_nd((1, 1, 1), (1, 1, 1))
      assert len(coords) == 3
      assert all(len(c) == 0 for c in coords)
  
imports: from skimage.draw import line_nd
  from skimage._shared.testing import assert_equal
label_desc: Use image node_id 1 for calling a global function with example usage: test_empty_line() without return types