code: def _conditional_variance(
      self, X: TensorType, F: TensorType
  ) -> tf.Tensor:
      raise NotImplementedError
  
imports: import abc
  from typing import Any, Callable, Iterable, Optional, Sequence, Union
  import tensorflow
  from check_shapes import check_shapes, inherit_check_shapes
  from ..base import MeanAndVariance, Module, TensorType
  from ..quadrature import GaussianQuadrature, NDiagGHQuadrature, ndiag_mc
label_desc: Use image node_id 7 for calling the Likelihood obj's underlying member method code with example usage: obj._conditional_variance(X, F) without return types