Write a text summary.

  Arguments:
    name: A name for this summary. The summary tag used for TensorBoard will
      be this name prefixed by any active name scopes.
    data: A UTF-8 string tensor value.
    step: Explicit `int64`-castable monotonic step value for this summary. If
      omitted, this defaults to `tf.summary.experimental.get_step()`, which must
      not be None.
    description: Optional long-form description for this summary, as a
      constant `str`. Markdown is supported. Defaults to empty.

  Returns:
    True on success, or false if no summary was emitted because no default
    summary writer was available.

  Raises:
    ValueError: if a default writer exists, but no step was provided and
      `tf.summary.experimental.get_step()` is None.

def text(name, data, step=None, description=None):
  """Write a text summary.

  Arguments:
    name: A name for this summary. The summary tag used for TensorBoard will
      be this name prefixed by any active name scopes.
    data: A UTF-8 string tensor value.
    step: Explicit `int64`-castable monotonic step value for this summary. If
      omitted, this defaults to `tf.summary.experimental.get_step()`, which must
      not be None.
    description: Optional long-form description for this summary, as a
      constant `str`. Markdown is supported. Defaults to empty.

  Returns:
    True on success, or false if no summary was emitted because no default
    summary writer was available.

  Raises:
    ValueError: if a default writer exists, but no step was provided and
      `tf.summary.experimental.get_step()` is None.
  """
  summary_metadata = metadata.create_summary_metadata(
      display_name=None, description=description)
  # TODO(https://github.com/tensorflow/tensorboard/issues/2109): remove fallback
  summary_scope = (
      getattr(tf.summary.experimental, 'summary_scope', None) or
      tf.summary.summary_scope)
  with summary_scope(
      name, 'text_summary', values=[data, step]) as (tag, _):
    tf.debugging.assert_type(data, tf.string)
    return tf.summary.write(
        tag=tag, tensor=data, step=step, metadata=summary_metadata)