src/charts/stacked-area.js
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);
        }
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);
        }
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); }
Orders the data by date for consumption on the chart tooltip
@param  {areaChartData} data    Chart data
@return {Object[]}               Chart data ordered by date
@private
Orders the data by date for consumption on the chart tooltip