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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 range(self, start_date=None, stop_date=None, field=lambda x: x.xfer):
 """Return a ``Transactions`` object in an inclusive date range. Args: start_date: A ``datetime.Date`` object that marks the inclusive start date for the range. stop_date: A ``datetime.Date`` object that marks the inclusive end date for the range. field: The field to compare start and end dates to. Default is the ``xfer`` field. Returns: A ``Transactions`` object. """

        assert start_date <= stop_date, \
            "Start date must be earlier than end date."

        out = Transactions()

        for t in self.trans:
            date = field(t)
            if (start_date is not None) and not (date >= start_date):
                continue
            if (stop_date is not None) and not (date <= stop_date):
                continue
            out.append(t)

        return out