code: 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=parseintervalf 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)
docs: 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.