code: def test_smoke_double_batch_kernel_double_batch_x_no_ard(self):
      kernel = self.create_kernel_no_ard(batch_shape=torch.Size([3, 2]))
      x = self.create_data_double_batch()
      batch_covar_mat = kernel(x).evaluate_kernel().to_dense()
      kernel(x, diag=True)
      return batch_covar_mat
  
imports: import pickle
  from abc import abstractmethod
  import torch
  from .base_test_case import BaseTestCase
label_desc: Use image node_id 12 for calling the BaseKernelTestCase obj's underlying member method code with example usage: obj.test_smoke_double_batch_kernel_double_batch_x_no_ard() and returns: batch_covar_mat