code: def match_time_series(self, timeseries1, timeseries2):
          
          time1 = map(lambda item: item[0], timeseries1.to_twodim_list())
          time2 = map(lambda item: item[0], timeseries2.to_twodim_list())
  
          matches = filter(lambda x: (x in time1), time2)
          listX  = filter(lambda x: (x[0] in matches), timeseries1.to_twodim_list())
          listY  = filter(lambda x: (x[0] in matches), timeseries2.to_twodim_list())
  
          return listX, listY
docs: Return two lists of the two input time series with matching dates
  
          :param TimeSeries timeseries1: The first timeseries
          :param TimeSeries timeseries2: The second timeseries
          :return:    Two two dimensional lists containing the matched values,
          :rtype:     two List