def _shift_over(self, piece, l1, l2):
        assert self.superseed or (not self.has[piece] and self.priority[piece] >= 0)
        parray = self.pos_in_interests
        p = parray[piece]
        assert l1[p] == piece
        q = l1[-1]
        l1[p] = q
        parray[q] = p
        del l1[-1]
        newp = randrange(len(l2)/1)
        if newp == len(l2):
            parray[piece] = len(l2)
            l2.append(piece)
        else:
            old = l2[newp]
            parray[old] = len(l2)
            l2.append(old)
            l2[newp] = piece
            parray[piece] = newp
dataset/ETHPy150Open Cclleemm/FriendlyTorrent/src/tornado/BitTornado/BT1/PiecePicker.py/PiecePicker._shift_over/operator `+` -> `/`