code: def test_chan_vese_gap_closing():
      ref = np.zeros((20, 20))
      ref[8:15, :] = np.ones((7, 20))
      img = ref.copy()
      img[:, 6] = np.zeros(20)
      result = chan_vese(
          img,
          mu=0.7,
          tol=1e-3,
          max_num_iter=1000,
          dt=1000,
          init_level_set="disk",
      ).astype(float)
      assert_array_equal(result, ref)
  
file_path: scikit-image/skimage/segmentation/tests/test_chan_vese.py
imports: import numpy
  import pytest
  from numpy.testing import assert_array_equal
  from skimage._shared.utils import _supported_float_type
  from skimage.segmentation import chan_vese
label_desc: Use image node_id 7 for calling a global function with example usage: test_chan_vese_gap_closing() without return types