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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, deltat=1.0):
        '''straight lines, with short life'''
        DNFZ.update(self, deltat)
        self.lifetime -= deltat
        if self.lifetime <= 0:
            self.randpos()
            self.lifetime = random.uniform(300,600)