javascript - HighCharts, Multiple Series, Async Drillup event -

i have highchart 3 series i'm using drilldown event asynchronously data each drilldown series. i've got working fine because can use drilldown event's, e.points determine if single series, or multiple series being drilled down into. thus, can keep track of i'm @ in sequence using drilldownlevel counter.

my issue on drillup event, event e not seem have attribute tells me if i'm drilling single or multiple series, drilldownlevel count gets decremented wrongly.

this i'm doing on drilldown

if ( !e.points ) {      // single series being drilled down      chart.addsingleseriesasdrilldown(e.point,  data.series[seriesindexes[e.point.color]]);      chart.hideloading();      chart.applydrilldown();      drilldownlevel++;      lastdrilldowntype = 0; } else {     // multiple series being drilled down     chart.addsingleseriesasdrilldown(e.point, data.series[seriesdrilldowneventcount]);     seriesdrilldowneventcount++;      if (seriesdrilldowneventcount === 3) {          seriesdrilldowneventcount = 0;          chart.hideloading();          chart.applydrilldown();          drilldownlevel++;          lastdrilldowntype = 1;      } } 

this i'm doing on drillup

if ( lastdrilldowntype === 0 ) {     // single series being drilled    seriesdrillupeventcount = 0;    drilldownlevel--; } else {    // multiple series being drilled     seriesdrillupeventcount++;    if (seriesdrillupeventcount === 3) {         seriesdrillupeventcount = 0;         drilldownlevel--;    } } 

lastdrilldowntype ends being incorrect after combination of drilling multiple series vs single series, , drilldownlevel count gets messed up.

does know of how use drillup event, e, determine type of series being drilled to?