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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def update(self, delta_seconds):
 """update tweeners. delta_seconds is time in seconds since last frame"""


        for obj in tuple(self.current_tweens):
            for tween in tuple(self.current_tweens[obj]):
                done = tween.update(delta_seconds)
                if done:
                    self.current_tweens[obj].remove(tween)
                    if tween.on_complete: tween.on_complete(tween.target)

            if not self.current_tweens[obj]:
                del self.current_tweens[obj]

        return self.current_tweens