class_docstr: Estimator class for TensorFlow models.
class_docstr_tok: ["Estimator","class","for","TensorFlow","models","."]
docstr: Get current TensorFlow session.
  
  :return: The current TensorFlow session.
docstr_tok: ["Get","current","TensorFlow","session",".",":","return",":","The","current","TensorFlow","session","."]
code: def sess(self) -> "tf.python.client.session.Session":
      """
      Get current TensorFlow session.
  
      :return: The current TensorFlow session.
      """
      if self._sess is not None:
          return self._sess
  
      raise NotImplementedError(
          "A valid TensorFlow session is not available."
      )
  
imports: import logging
  from typing import Any, Tuple, TYPE_CHECKING
  import numpy
  from art import config
  from art.estimators.estimator import BaseEstimator, LossGradientsMixin, NeuralNetworkMixin
label_desc: Use image node_id 4 for calling the TensorFlowEstimator obj's underlying member method code with example usage: obj.sess() and returns: self