code: def _ensure_tf_install():
      """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_hub. This is so that "
              "users can decide which tensorflow package to use. "
              "To use tensorflow_hub, please install a current version of tensorflow "
              "by following the instructions at https://tensorflow.org/install and "
              "https://tensorflow.org/hub/installation.\n\n"
          )
          raise
  
      from pkg_resources import parse_version
  
      #
      # Update this whenever we need to depend on a newer TensorFlow release.
      #
      # NOTE: Put only numeric release versions here, like "1.2.3", and be aware
      # that they will also allow release candidates and even any nightly build
      # starting just after the previous release was cut. That's because
      # pkg_resources.parse_version does not understand 'dev' and 'rc' tags;
      # it just does a lexicgraphic comparison after splitting on dots
      # and character class transitions.
      #
      required_tensorflow_version = "1.15.0"
      if parse_version(tf.__version__) < parse_version(
          required_tensorflow_version
      ):
          raise ImportError(
              "\n\nThis version of tensorflow_hub requires tensorflow "
              "version >= {required}; Detected an installation of version {present}. "
              "To proceed, please upgrade tensorflow by following the instructions "
              "at https://tensorflow.org/install and "
              "https://tensorflow.org/hub/installation.\n\n".format(
                  required=required_tensorflow_version,
                  present=tf.__version__,
              )
          )
  
file_path: hub/tensorflow_hub/__init__.py
imports: from tensorflow_hub.keras_layer import KerasLayer
  from tensorflow_hub.module_v2 import load
  from tensorflow_hub.module_v2 import resolve
  from tensorflow_hub.version import __version__
  from tensorflow_hub.config import _run, _get_extra_deps
label_desc: Use image node_id 2 for calling a global function with example usage: _ensure_tf_install() without return types