code: def _fold_status(self, dt_utc, dt_wall):
          
          if self.is_ambiguous(dt_wall):
              delta_wall = dt_wall - dt_utc
              _fold = int(delta_wall == (dt_utc.utcoffset() - dt_utc.dst()))
          else:
              _fold = 0
  
          return _fold
docs: Determine the fold status of a "wall" datetime, given a representation
          of the same datetime as a (naive) UTC datetime. This is calculated based
          on the assumption that ``dt.utcoffset() - dt.dst()`` is constant for all
          datetimes, and that this offset is the actual number of hours separating
          ``dt_utc`` and ``dt_wall``.
  
          :param dt_utc:
              Representation of the datetime as UTC
  
          :param dt_wall:
              Representation of the datetime as "wall time". This parameter must
              either have a `fold` attribute or have a fold-naive
              :class:`datetime.tzinfo` attached, otherwise the calculation may
              fail.