code: def test_fantasize(self) -> None:
      for batch_shape, likelihood_cls in itertools.product(
          (torch.Size(), torch.Size([2])),
          (PairwiseLogitLikelihood, PairwiseProbitLikelihood),
      ):
          tkwargs = {"device": self.device, "dtype": self.dtype}
          X_dim = 2
  
          model, _ = self._get_model_and_data(
              batch_shape=batch_shape,
              X_dim=X_dim,
              likelihood_cls=likelihood_cls,
          )
  
          # fantasize
          X_f = torch.rand(
              torch.Size(batch_shape + torch.Size([4, X_dim])),
              **tkwargs,
          )
          sampler = PairwiseSobolQMCNormalSampler(
              sample_shape=torch.Size([3])
          )
          fm = model.fantasize(X=X_f, sampler=sampler)
          self.assertIsInstance(fm, model.__class__)
  
imports: import itertools
  import random
  import warnings
  from typing import Dict, Tuple, Union
  import torch
  from botorch.acquisition.objective import ScalarizedPosteriorTransform
  from botorch.exceptions import OptimizationWarning, UnsupportedError
  from botorch.exceptions.warnings import _get_single_precision_warning, InputDataWarning
  from botorch.fit import fit_gpytorch_mll
  from botorch.models.likelihoods.pairwise import PairwiseLikelihood, PairwiseLogitLikelihood, PairwiseProbitLikelihood
  from botorch.models.model import Model
  from botorch.models.pairwise_gp import _ensure_psd_with_jitter, PairwiseGP, PairwiseLaplaceMarginalLogLikelihood
  from botorch.models.transforms.input import Normalize
  from botorch.posteriors import GPyTorchPosterior
  from botorch.sampling.pairwise_samplers import PairwiseSobolQMCNormalSampler
  from botorch.utils.testing import BotorchTestCase
  from gpytorch.kernels import RBFKernel, ScaleKernel
  from gpytorch.kernels.linear_kernel import LinearKernel
  from gpytorch.means import ConstantMean
  from gpytorch.priors import GammaPrior, SmoothedBoxPrior
  from linear_operator.utils.errors import NotPSDError
  from torch import Tensor
label_desc: Use image node_id 7 for calling the TestPairwiseGP obj's underlying member method code with example usage: obj.test_fantasize() without return types