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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 _remove(self, timer):
 """Remove timer from heap lock and presence are assumed"""

        assert timer.timer_heap == self
        del self.timers[timer]
        assert timer in self.heap
        self.heap.remove(timer)
        heapq.heapify(self.heap)