code: def test_nlmeans_static():
      S0 = 100 * np.ones((20, 20, 20), dtype="f8")
      S0nb = non_local_means(S0, sigma=1.0, rician=False)
      assert_array_almost_equal(S0, S0nb)
  
file_path: dipy/dipy/denoise/tests/test_non_local_means.py
imports: import numpy
  from numpy.testing import assert_, assert_equal, assert_array_almost_equal, assert_raises
  from dipy.denoise.non_local_means import non_local_means
  from dipy.testing.decorators import set_random_number_generator
label_desc: Use image node_id 1 for calling a global function with example usage: test_nlmeans_static() without return types