code: def test_roots(self):
      # regression test for gh-6357: .roots method should work
      p = pchip([0, 1], [-1, 1])
      r = p.roots()
      assert_allclose(r, 0.5)
  
imports: import warnings
  import io
  import numpy
  from numpy.testing import assert_almost_equal, assert_array_equal, assert_array_almost_equal, assert_allclose, assert_equal, assert_
  from pytest import raises
  from scipy.interpolate import KroghInterpolator, krogh_interpolate, BarycentricInterpolator, barycentric_interpolate, approximate_taylor_polynomial, CubicHermiteSpline, pchip, PchipInterpolator, pchip_interpolate, Akima1DInterpolator, CubicSpline, make_interp_spline
label_desc: Use image node_id 10 for calling the TestPCHIP obj's underlying member method code with example usage: obj.test_roots() without return types