code: def test_univariate_polynomial_smoother():
      x = np.linspace(0, 1, 5)
      pol = UnivariatePolynomialSmoother(x, degree=3)
      assert_equal(pol.basis.shape, (5, 3))
      assert_allclose(pol.basis[:, 2], x.ravel() ** 3)
  
imports: import pytest
  import numpy
  from numpy.testing import assert_allclose, assert_equal
  from statsmodels.gam.smooth_basis import UnivariatePolynomialSmoother, PolynomialSmoother, BSplines
label_desc: Use image node_id 1 for calling a global function with example usage: test_univariate_polynomial_smoother() without return types