def METHOD_NAME(self, display_object):
    """Append a display object as an output.
    Parameters
    ----------
    display_object : IPython.core.display.DisplayObject
        The object to display (e.g., an instance of
        `IPython.display.Markdown` or `IPython.display.Image`).
    """
    fmt = InteractiveShell.instance().display_formatter.format
    data, metadata = fmt(display_object)
    self.outputs += (
        {
            'output_type': 'display_data',
            'data': data,
            'metadata': metadata
        },
    )