message: In Metrics spans disappear in mouseOver
diff: @@ -322,7 +322,9 @@ class ChartWithLegend<T extends RichDataPoint, O extends LineInfo> extends React
  serieID: serieID,
  onMouseOver: props => {
  this.mouseOnLegend = true;
  - return {
  + return serieName === 'overlay'
  + ? null
  + : {
  style: { ...props.style, strokeWidth: 4, fillOpacity: 0 }
  };
  },
  