code: def test_two_points(self):
      # regression test for gh-6222: pchip([0, 1], [0, 1]) fails because
      # it tries to use a three-point scheme to estimate edge derivatives,
      # while there are only two points available.
      # Instead, it should construct a linear interpolator.
      x = np.linspace(0, 1, 11)
      p = pchip([0, 1], [0, 2])
      assert_allclose(p(x), 2 * x, atol=1e-15)
  
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 8 for calling the TestPCHIP obj's underlying member method code with example usage: obj.test_two_points() without return types