code: def test_edge_detect():
      img = np.zeros((10, 10))
      img[:5] = 1
      _, edge_mask = _edge_detect(img)
      assert np.allclose(img[4], 1)
  
imports: import numpy
  from ..edge_detect import _edge_detect, _fast_abs_percentile
label_desc: Use image node_id 2 for calling a global function with example usage: test_edge_detect() without return types