code: def __init__(self, train_x, train_y):
      likelihood = gpytorch.likelihoods.GaussianLikelihood()
      super().__init__(train_x, train_y, likelihood)
      self.mean_module = gpytorch.means.ZeroMean()
      self.covar_module = gpytorch.kernels.ScaleKernel(
          RFFKernel(num_samples=50)
      )
  
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 1 to create a new TestModel object from inherited base classes: gpytorch.models with example: obj = TestModel(train_x, train_y)