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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 _maybe_apply_time_shift(da, time_offset=None, **DataAttrs):
 """Correct off-by-one error in GFDL instantaneous model data. Instantaneous data that is outputted by GFDL models is generally off by one timestep. For example, a netCDF file that is supposed to correspond to 6 hourly data for the month of January, will have its last time value be in February. """

        if time_offset is not None:
            time = times.apply_time_offset(da[TIME_STR], **time_offset)
            da[TIME_STR] = time
        else:
            if DataAttrs['dtype_in_time'] == 'inst':
                if DataAttrs['intvl_in'].endswith('hr'):
                    offset = -1 * int(DataAttrs['intvl_in'][0])
                else:
                    offset = 0
                time = times.apply_time_offset(da[TIME_STR], hours=offset)
                da[TIME_STR] = time
        return da