<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def rebase_event(self, event):
 """ Rebase the coordinates of the passed event to frame-relative coordinates. :param event: The event to be rebased. :returns: A new event object appropriately re-based. """

        new_event = copy(event)
        if isinstance(new_event, MouseEvent):
            origin = self._canvas.origin
            new_event.x -= origin[0]
            new_event.y -= origin[1] - self._canvas.start_line
        logger.debug("New event: %s", new_event)
        return new_event