code: def _ensure_tf_install():  # pylint: disable=g-statement-before-imports
      """Attempt to import tensorflow, and ensure its version is sufficient.
  
      Raises:
        ImportError: if either tensorflow is not importable or its version is
        inadequate.
      """
      try:
          import tensorflow as tf
      except ImportError:
          # Print more informative error message, then reraise.
          print(
              "\n\nFailed to import TensorFlow. Please note that TensorFlow is not "
              "installed by default when you install TensorFlow Model Optimization. This "
              "is so that users can decide whether to install the GPU-enabled "
              "TensorFlow package. To use TensorFlow Model Optimization, please install "
              "the most recent version of TensorFlow, by following instructions at "
              "https://tensorflow.org/install.\n\n"
          )
          raise
  
      import distutils.version
  
      #
      # Update this whenever we need to depend on a newer TensorFlow release.
      #
      required_tensorflow_version = "1.14.0"
  
      if distutils.version.LooseVersion(
          tf.version.VERSION
      ) < distutils.version.LooseVersion(required_tensorflow_version):
          raise ImportError(
              "This version of TensorFlow Model Optimization requires TensorFlow "
              "version >= {required}; Detected an installation of version {present}. "
              "Please upgrade TensorFlow to proceed.".format(
                  required=required_tensorflow_version,
                  present=tf.__version__,
              )
          )
  
file_path: model-optimization/tensorflow_model_optimization/__init__.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import inspect
  import os
  import sys
  from tensorflow_model_optimization.python.core import version
  from tensorflow_model_optimization.python.core.api import clustering
  from tensorflow_model_optimization.python.core.api import experimental
  from tensorflow_model_optimization.python.core.api import quantization
  from tensorflow_model_optimization.python.core.api import sparsity
label_desc: Use image node_id 1 for calling a global function with example usage: _ensure_tf_install() without return types