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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _pywrap_tensorflow():
 """Provide pywrap_tensorflow access in TensorBoard. pywrap_tensorflow cannot be accessed from tf.python.pywrap_tensorflow and needs to be imported using `from tensorflow.python import pywrap_tensorflow`. Therefore, we provide a separate accessor function for it here. NOTE: pywrap_tensorflow is not part of TensorFlow API and this dependency will go away soon. Returns: pywrap_tensorflow import, if available. Raises: ImportError: if we couldn't import pywrap_tensorflow. """

  try:
    from tensorboard.compat import notf  # pylint: disable=g-import-not-at-top
  except ImportError:
    try:
      from tensorflow.python import pywrap_tensorflow  # pylint: disable=g-import-not-at-top
      return pywrap_tensorflow
    except ImportError:
      pass
  from tensorboard.compat.tensorflow_stub import pywrap_tensorflow  # pylint: disable=g-import-not-at-top
  return pywrap_tensorflow