How to use the ipycanvas.canvas._CanvasBase function in ipycanvas

if content.get('event', '') == 'mouse_up':
            self._mouse_up_callbacks(content['x'], content['y'])
        if content.get('event', '') == 'mouse_out':
            self._mouse_out_callbacks(content['x'], content['y'])

        if content.get('event', '') == 'touch_start':
            self._touch_start_callbacks([(touch['x'], touch['y']) for touch in content['touches']])
        if content.get('event', '') == 'touch_end':
            self._touch_end_callbacks([(touch['x'], touch['y']) for touch in content['touches']])
        if content.get('event', '') == 'touch_move':
            self._touch_move_callbacks([(touch['x'], touch['y']) for touch in content['touches']])
        if content.get('event', '') == 'touch_cancel':
            self._touch_cancel_callbacks([(touch['x'], touch['y']) for touch in content['touches']])


class MultiCanvas(_CanvasBase):
    """Create a MultiCanvas widget with n_canvases Canvas widgets.

    Args:
        n_canvases (int): The number of canvases to create
        width (int): The width (in pixels) of the canvases
        height (int): The height (in pixels) of the canvases
    """

    _model_name = Unicode('MultiCanvasModel').tag(sync=True)
    _view_name = Unicode('MultiCanvasView').tag(sync=True)

    _canvases = List(Instance(Canvas)).tag(sync=True, **widget_serialization)

    def __init__(self, n_canvases=3, *args, **kwargs):
        """Constructor."""
        super(MultiCanvas, self).__init__(*args, _canvases=[Canvas() for _ in range(n_canvases)], **kwargs)

    @property
    def size(self):
        """Get the canvas size."""
        return (self.width, self.height)

    @size.setter
    def size(self, value):
        """Set the size of the canvas, this is deprecated, use width and height attributes instead."""
        warnings.warn(
            'size is deprecated and will be removed in a future release, please use width and height instead.',
            DeprecationWarning
        )
        (self.width, self.height) = value


class Canvas(_CanvasBase):
    """Create a Canvas widget.

    Args:
        width (int): The width (in pixels) of the canvas
        height (int): The height (in pixels) of the canvas
        caching (boolean): Whether commands should be cached or not
    """

    _model_name = Unicode('CanvasModel').tag(sync=True)
    _view_name = Unicode('CanvasView').tag(sync=True)

    #: (valid HTML color) The color for filling rectangles and paths. Default to ``'black'``.
    fill_style = Color('black')

    #: (valid HTML color) The color for rectangles and paths stroke. Default to ``'black'``.
    stroke_style = Color('black')