def METHOD_NAME(self, notification, icon=None):
    '''
    Set the small application icon displayed at the top panel together with
    WiFi, battery percentage and time and the big optional icon (preferably
    PNG format with transparent parts) displayed directly in the
    notification body.
    .. versionadded:: 1.4.0
    '''
    app_icon = self._app_icon
    notification.setSmallIcon(app_icon)
    bitmap_icon = app_icon
    if icon is not None:
        bitmap_icon = BitmapFactory.decodeFile(icon)
        notification.setLargeIcon(bitmap_icon)
    elif icon == '':
        # we don't want the big icon set,
        # only the small one in the top panel
        pass
    else:
        bitmap_icon = BitmapFactory.decodeResource(
            python_act.getResources(), app_icon
        )
        notification.setLargeIcon(bitmap_icon)