code: def test_smoothing_misfit(self, xp, scp, kernel):
      # Make sure we can find a smoothing parameter for each kernel that
      # removes a sufficient amount of noise.
      rng = _np.random.RandomState(0)
      seq = Halton(1, scramble=False, seed=rng)
  
      noise = 0.2
      rmse_tol = 0.1
      smoothing_range = 10 ** xp.linspace(-4, 1, 20)
  
      x = xp.asarray(3 * seq.random(100))
      y = _1d_test_function(x, xp) + xp.asarray(
          rng.normal(0.0, noise, (100,))
      )
      ytrue = _1d_test_function(x, xp)
      rmse_within_tol = False
      for smoothing in smoothing_range:
          ysmooth = self.build(
              scp, x, y, epsilon=1.0, smoothing=smoothing, kernel=kernel
          )(x)
          rmse = xp.sqrt(xp.mean((ysmooth - ytrue) ** 2))
          if rmse < rmse_tol:
              rmse_within_tol = True
              break
  
      assert rmse_within_tol
      return ysmooth
  
imports: import pickle
  import pytest
  import warnings
  import numpy
  from numpy.linalg import LinAlgError
  import cupy
  import cupyx
  from cupy import testing
  import cupyx.scipy.interpolate
  from cupyx.scipy.interpolate._rbfinterp import _AVAILABLE, _SCALE_INVARIANT, _NAME_TO_MIN_DEGREE, NAME_TO_FUNC, _monomial_powers, polynomial_matrix, kernel_matrix
label_desc: Use image node_id 9 for calling the _TestRBFInterpolator obj's underlying member method code with example usage: obj.test_smoothing_misfit(xp, scp, kernel) and returns: ysmooth