code: function reducer(individualSeries, initialFunction, reductionFunction) {
                          if (individualSeries.length == 0) {
                              return NaN;
                          }
                          var initial = initialFunction(individualSeries[0][1]);
                          var i=1;
                          for (; initial==null && i<individualSeries.length; i++) {
                              initial = initialFunction(individualSeries[i][1]);
                          }
                          for (; i<individualSeries.length; i++) {
                              if (individualSeries[i][1] != null) {
                                  initial = reductionFunction(initial, individualSeries[i][1]);
                              }
                          }
                          return initial;
                      }
docs: do sorting before we parse