code: function getDataByDate(data) {
              return d3Collection.nest()
                  .key(getDate)
                  .entries(
                      data.sort((a, b) => a.date - b.date)
                  )
                  .map(d => {
                      return assign({}, d, {
                          date: new Date(d.key)
                      });
                  });
  
              // let b =  d3Collection.nest()
              //                     .key(getDate).sortKeys(d3Array.ascending)
              //                     .entries(data);
          }
docs: Orders the data by date for consumption on the chart tooltip
  @param  {areaChartData} data    Chart data
  @return {Object[]}               Chart data ordered by date
  @private