code: def test_epsilon_not_specified_error(self, xp, scp, kernel):
      if kernel in _SCALE_INVARIANT:
          return True
  
      y = xp.linspace(0, 1, 5)[:, None]
      d = xp.zeros(5)
      self.build(scp, y, d, kernel=kernel)
  
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 16 for calling the _TestRBFInterpolator obj's underlying member method code with example usage: obj.test_epsilon_not_specified_error(xp, scp, kernel) and returns: True