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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 sort_timeseries(self, ascending=True):
 """Sorts the data points within the TimeSeries according to their occurrence inline. :param boolean ascending: Determines if the TimeSeries will be ordered ascending or descending. If this is set to descending once, the ordered parameter defined in :py:meth:`TimeSeries.__init__` will be set to False FOREVER. :return: Returns :py:obj:`self` for convenience. :rtype: TimeSeries """

        # the time series is sorted by default
        if ascending and self._sorted:
            return

        sortorder = 1
        if not ascending:
            sortorder = -1
            self._predefinedSorted = False

        self._timeseriesData.sort(key=lambda i: sortorder * i[0])

        self._sorted = ascending

        return self