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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 localize(dt, force_to_local=True):
 """Localize a datetime to the local timezone. If dt is naive, returns the same datetime with the local timezone, otherwise uses astimezone to convert. Args: dt: datetime object. force_to_local: Force all results to be in local time. Returns: A datetime_tz object. """

  if not isinstance(dt, datetime_tz):
    if not dt.tzinfo:
      return datetime_tz(dt, tzinfo=localtz())
    dt = datetime_tz(dt)
  if force_to_local:
    return dt.astimezone(localtz())
  return dt