code: def _check_accuracy(
      self, func, x=None, tol=1e-6, alternate=False, rescale=False, **kw
  ):
      np.random.seed(1234)
      if x is None:
          x = np.array(
              [
                  (0, 0),
                  (0, 1),
                  (1, 0),
                  (1, 1),
                  (0.25, 0.75),
                  (0.6, 0.8),
                  (0.5, 0.2),
              ],
              dtype=float,
          )
  
      if not alternate:
          ip = interpnd.CloughTocher2DInterpolator(
              x, func(x[:, 0], x[:, 1]), tol=1e-6, rescale=rescale
          )
      else:
          ip = interpnd.CloughTocher2DInterpolator(
              (x[:, 0], x[:, 1]),
              func(x[:, 0], x[:, 1]),
              tol=1e-6,
              rescale=rescale,
          )
  
      p = np.random.rand(50, 2)
  
      if not alternate:
          a = ip(p)
      else:
          a = ip(p[:, 0], p[:, 1])
      b = func(p[:, 0], p[:, 1])
  
      try:
          assert_allclose(a, b, **kw)
      except AssertionError:
          print("_check_accuracy: abs(a-b):", abs(a - b))
          print("ip.grad:", ip.grad)
          raise
  
imports: import os
  import numpy
  from numpy.testing import assert_equal, assert_allclose, assert_almost_equal, suppress_warnings
  from pytest import raises
  import pytest
  import scipy.interpolate.interpnd
  import scipy.spatial.qhull
  import pickle
label_desc: Use image node_id 1 for calling the TestCloughTocher2DInterpolator obj's underlying member method code with example usage: obj._check_accuracy(func, x, tol, alternate, rescale) without return types