code: def stats(self, start, end, fields=None):
          '''Perform a multivariate statistic calculation of this
  :class:`ColumnTS` from a *start*  date/datetime to an
  *end* date/datetime.
  
  :param start: Start date for analysis.
  :param end: End date for analysis.
  :param fields: Optional subset of :meth:`fields` to perform analysis on.
      If not provided all fields are included in the analysis.
  '''
          start = self.pickler.dumps(start)
          end = self.pickler.dumps(end)
          backend = self.read_backend
          return backend.execute(
              backend.structure(self).stats(start, end, fields), self._statsf stats(self, start, end, fields=None):
          '''Perform a multivariate statistic calculation of this
  :class:`ColumnTS` from a *start*  date/datetime to an
  *end* date/datetime.
  
  :param start: Start date for analysis.
  :param end: End date for analysis.
  :param fields: Optional subset of :meth:`fields` to perform analysis on.
      If not provided all fields are included in the analysis.
  '''
          start = self.pickler.dumps(start)
          end = self.pickler.dumps(end)
          backend = self.read_backend
          return backend.execute(
              backend.structure(self).stats(start, end, fields), self._stats)
docs: Perform a multivariate statistic calculation of this
  :class:`ColumnTS` from a *start*  date/datetime to an
  *end* date/datetime.
  
  :param start: Start date for analysis.
  :param end: End date for analysis.
  :param fields: Optional subset of :meth:`fields` to perform analysis on.
      If not provided all fields are included in the analysis.