code: def test_kernel_getitem_single_batch(self):
      kernel = self.create_kernel_no_ard(batch_shape=torch.Size([2]))
      x = self.create_data_single_batch()
  
      res1 = kernel(x).to_dense()[
          0
      ]  # Result of first kernel on first batch of data
      randn_weights = kernel.randn_weights
  
      new_kernel = kernel[0]
      new_kernel._init_weights(randn_weights=randn_weights[0])
      res2 = new_kernel(
          x[0]
      ).to_dense()  # Should also be result of first kernel on first batch of data.
  
      self.assertLess(torch.norm(res1 - res2) / res1.norm(), 1e-4)
  
imports: import unittest
  from unittest.mock import MagicMock, patch
  import linear_operator
  import torch
  import gpytorch
  from gpytorch.kernels import RFFKernel
  from gpytorch.test.base_kernel_test_case import BaseKernelTestCase
label_desc: Use image node_id 5 for calling the TestRFFKernel obj's underlying member method code with example usage: obj.test_kernel_getitem_single_batch() without return types