code: def test_active_dims_list(self):
      x = self.create_data_no_batch()
      kernel = self.create_kernel(num_dims=4, active_dims=[0, 2, 4, 6])
      y = torch.randn_like(x[..., 0])
      kernel.initialize_from_data(x, y)
      kernel.initialize_from_data_empspect(x, y)
  
      covar_mat = kernel(x).evaluate_kernel().to_dense()
      kernel_basic = self.create_kernel(num_dims=4)
      kernel_basic.raw_mixture_weights.data = kernel.raw_mixture_weights
      kernel_basic.raw_mixture_means.data = kernel.raw_mixture_means
      kernel_basic.raw_mixture_scales.data = kernel.raw_mixture_scales
      covar_mat_actual = (
          kernel_basic(x[:, [0, 2, 4, 6]]).evaluate_kernel().to_dense()
      )
  
      self.assertLess(
          torch.norm(covar_mat - covar_mat_actual)
          / covar_mat_actual.norm(),
          1e-4,
      )
  
file_path: gpytorch/test/kernels/test_spectral_mixture_kernel.py
imports: import unittest
  import torch
  from gpytorch.kernels import SpectralMixtureKernel
label_desc: Use image node_id 5 for calling the TestSpectralMixtureKernel obj's underlying member method code with example usage: obj.test_active_dims_list() without return types