handleLegendItemTapped method
Implementation
@override
void handleLegendItemTapped(LegendItem item, bool isToggled) {
  super.handleLegendItemTapped(item, isToggled);
  final PyramidLegendItem legendItem = item as PyramidLegendItem;
  final int toggledIndex = legendItem.pointIndex;
  segments[toggledIndex].isVisible = !isToggled;
  canUpdateOrCreateSegments = true;
  markNeedsLayout();
  legendItem.onToggled?.call();
}