<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def add_subvisual(self, visual):
 """Add a subvisual Parameters visual : instance of Visual The visual to add. """

        visual.transforms = self.transforms
        visual._prepare_transforms(visual)
        self._subvisuals.append(visual)
        visual.events.update.connect(self._subv_update)
        self.update()