class_docstr: A class to turn legacy mode parameters into hyperparameters.
  
  It also disables the ``model_dir`` hyperparameter, and set the
  image URI when instantiating a TensorFlow estimator.
docstr: Returns the AWS region for constructing an ECR image URI.
docstr_tok: ["Returns","the","AWS","region","for","constructing","an","ECR","image","URI","."]
code: def region(self):
      """Returns the AWS region for constructing an ECR image URI."""
      if self._region is None:
          self._region = boto3.Session().region_name
  
      return self._region
  
imports: from __future__ import absolute_import
  import ast
  import boto3
  import six
  from sagemaker.cli.compatibility.v2.modifiers import framework_version, matching
  from sagemaker.cli.compatibility.v2.modifiers.modifier import Modifier
  from sagemaker import image_uris
label_desc: Use image node_id 2 for calling the TensorFlowLegacyModeConstructorUpgrader obj's underlying member method code with example usage: obj.region() and returns: self