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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 call_next(self):
 """Set next hop in the loop. Call task"""

        if self.handle is not None:
            self.handle.cancel()
        next_time = self.get_next()
        self.handle = self.loop.call_at(next_time, self.call_next)
        self.call_func()