<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def on_resize(self, event):
 """Resize the OpenGL context."""

        self.context.set_viewport(0, 0, event.size[0], event.size[1])
        for visual in self.visuals:
            visual.on_resize(event.size)
        self.update()