docs: def cast_naive_datetime_to_tz(dt, tz=UTC()):
      """If datetime is tz-naive, set it to ``tz``. If datetime is tz-aware, return it
      unmodified.
  
      Args:
        dt : datetime
          tz-naive or tz-aware datetime.
  
        tz : datetime.tzinfo
          The timezone to which to adjust tz-naive datetime.
  
      Returns:
        datetime
          tz-aware datetime.
  
      Warning:
        This will change the actual moment in time that is represented if the datetime is
        naive and represents a date and time not in ``tz``.
  
      See Also:
        ``normalize_datetime_to_utc()``
  
      """
      if has_tz(dt):
          return dt
      return dt.replace(tzinfo=tz)