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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 _new_lnotab(instrs, lnotab):
 """The updated lnotab after the instructions have been transformed. Parameters instrs : iterable[Instruction] The new instructions. lnotab : dict[Instruction -> int] The lnotab for the old code object. Returns ------- new_lnotab : dict[Instruction -> int] The post transform lnotab. """

    return {
        lno: _a_if_not_none(instr._stolen_by, instr)
        for lno, instr in lnotab.items()
    }