code: def test_stationary(self):
      kernel = ScaleKernel(RBFKernel())
      self.assertTrue(kernel.is_stationary)
  
imports: import pickle
  import unittest
  import torch
  from gpytorch.kernels import LinearKernel, RBFKernel, ScaleKernel
  from gpytorch.priors import NormalPrior
  from gpytorch.test.base_kernel_test_case import BaseKernelTestCase
label_desc: Use image node_id 7 for calling the TestScaleKernel obj's underlying member method code with example usage: obj.test_stationary() without return types