code: def tf2():
    
    # Import the `tf` compat API from this file and check if it's already TF 2.0.
    if tf.__version__.startswith('2.'):
      return tf
    elif hasattr(tf, 'compat') and hasattr(tf.compat, 'v2'):
      # As a fallback, try `tensorflow.compat.v2` if it's defined.
      return tf.compat.v2
    raise ImportError('cannot import tensorflow 2.0 API')
docs: Provide the root module of a TF-2.0 API for use within TensorBoard.
  
    Returns:
      The root module of a TF-2.0 API, if available.
  
    Raises:
      ImportError: if a TF-2.0 API is not available.