code: def test_nlmeans_static():
      S0 = 100 * np.ones((20, 20, 20), dtype="f8")
      S0n = nlmeans(S0, sigma=np.ones((20, 20, 20)), rician=False)
      assert_array_almost_equal(S0, S0n)
  
file_path: dipy/dipy/denoise/tests/test_nlmeans.py
imports: from time import time
  import numpy
  from numpy.testing import assert_, assert_equal, assert_array_almost_equal, assert_raises
  import pytest
  from dipy.denoise.nlmeans import nlmeans
  from dipy.denoise.denspeed import add_padding_reflection, remove_padding
  from dipy.utils.omp import cpu_count, have_openmp
  from dipy.testing import assert_greater
  from dipy.testing.decorators import set_random_number_generator
label_desc: Use image node_id 2 for calling a global function with example usage: test_nlmeans_static() without return types