code: def test_nnls(self):
      a = arange(25.0).reshape(-1, 5)
      x = arange(5.0)
      y = dot(a, x)
      x, res = nnls(a, y)
      assert_(res < 1e-7)
      assert_(norm(dot(a, x) - y) < 1e-7)
  
file_path: catboost/contrib/python/scipy/py3/scipy/optimize/tests/test_nnls.py
imports: import numpy
  from numpy.testing import assert_
  from pytest import raises
  from scipy.optimize import nnls
  from numpy import arange, dot
  from numpy.linalg import norm
label_desc: Use image node_id 1 for calling the TestNNLS obj's underlying member method code with example usage: obj.test_nnls() without return types