code: def _check_predictions_exact_gp(
      self,
      model: ExactGP,
      test_x: torch.Tensor,
      test_y: torch.Tensor,
      atol: float,
  ):
      with settings.observation_nan_policy("mask"):
          prediction = model(test_x)
          self._check_prediction(prediction, test_y, atol)
  
      clear_cache_hook(model.prediction_strategy)
  
      with settings.observation_nan_policy("fill"), self.assertWarns(
          RuntimeWarning, msg=self.warning
      ):
          prediction = model(test_x)
          self._check_prediction(prediction, test_y, atol)
  
      clear_cache_hook(model.prediction_strategy)
  
      with settings.observation_nan_policy("mask"):
          model(test_x)
      with settings.observation_nan_policy("fill"), self.assertWarns(
          RuntimeWarning, msg=self.warning
      ):
          prediction = model(test_x)
          self._check_prediction(prediction, test_y, atol)
  
      clear_cache_hook(model.prediction_strategy)
  
      with settings.observation_nan_policy("fill"), self.assertWarns(
          RuntimeWarning, msg=self.warning
      ):
          model(test_x)
      with settings.observation_nan_policy("mask"):
          prediction = model(test_x)
          self._check_prediction(prediction, test_y, atol)
  
imports: import unittest
  import torch
  from gpytorch import settings
  from gpytorch import ExactMarginalLogLikelihood
  from gpytorch.distributions import MultivariateNormal, MultitaskMultivariateNormal
  from gpytorch.kernels import ScaleKernel, RBFKernel, MultitaskKernel
  from gpytorch.likelihoods import GaussianLikelihood, Likelihood, MultitaskGaussianLikelihood
  from gpytorch.means import ConstantMean, MultitaskMean
  from gpytorch.mlls import PredictiveLogLikelihood, MarginalLogLikelihood, VariationalELBO
  from gpytorch.models import ExactGP, VariationalGP, GP
  from gpytorch.test.base_test_case import BaseTestCase
  from gpytorch.utils.memoize import clear_cache_hook
  from gpytorch.variational import CholeskyVariationalDistribution, LMCVariationalStrategy, VariationalStrategy
label_desc: Use image node_id 2 for calling the TestMissingData obj's underlying member method code with example usage: obj._check_predictions_exact_gp(model, test_x, test_y, atol) without return types