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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 intervals(self, startdate, enddate, parseinterval=None):
        '''Given a ``startdate`` and an ``enddate`` dates, evaluate the
        date intervals from which data is not available. It return a list
        of two-dimensional tuples containing start and end date for the
        interval. The list could contain 0, 1 or 2 tuples.'''
        return missing_intervals(startdate, enddate, self.data_start,
                                 self.data_end, dateconverter=self.todate,
                                 parseinterval=parseinterval)