def _free(self, block):
        # free location and try to merge with neighbours
        (arena, start, stop) = block

        try:
            prev_block = self._stop_to_block[(arena, start)]
        except KeyError:
            pass
        else:
            start, _ = self._absorb(prev_block)

        try:
            next_block = self._start_to_block[(arena, stop)]
        except __HOLE__:
            pass
        else:
            _, stop = self._absorb(next_block)

        block = (arena, start, stop)
        length = stop - start

        try:
            self._len_to_seq[length].append(block)
        except KeyError:
            self._len_to_seq[length] = [block]
            bisect.insort(self._lengths, length)

        self._start_to_block[(arena, start)] = block
        self._stop_to_block[(arena, stop)] = block
dataset/ETHPy150Open deanhiller/databus/webapp/play1.3.x/python/Lib/multiprocessing/heap.py/Heap._free