code: def test_no_nans():
      """Test that `match_template` doesn't return NaN values.
  
      When image values are only slightly different, floating-point errors can
      cause a subtraction inside of a square root to go negative (without an
      explicit check that was added to `match_template`).
      """
      np.random.seed(1)
      image = 0.5 + 1e-9 * np.random.normal(size=(20, 20))
      template = np.ones((6, 6))
      template[:3, :] = 0
      result = match_template(image, template)
      assert not np.any(np.isnan(result))
  
file_path: scikit-image/skimage/feature/tests/test_template.py
imports: import numpy
  from skimage._shared.testing import assert_almost_equal, assert_equal
  from skimage import data, img_as_float
  from skimage.morphology import diamond
  from skimage.feature import match_template, peak_local_max
  from skimage._shared import testing
label_desc: Use image node_id 3 for calling a global function with example usage: test_no_nans() without return types