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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 _get_crop_target(target_px:Union[int,TensorImageSize], mult:int=None)->Tuple[int,int]:
    "Calc crop shape of `target_px` to nearest multiple of `mult`."
    target_r,target_c = tis2hw(target_px)
    return _round_multiple(target_r,mult),_round_multiple(target_c,mult)