isDatumSelected method
Implementation
bool isDatumSelected(ImmutableSeries<D> series, int? index) {
  final Object? datum = index == null ? null : series.data[index];
  return _selectedDatum.contains(SeriesDatum(series, datum));
}bool isDatumSelected(ImmutableSeries<D> series, int? index) {
  final Object? datum = index == null ? null : series.data[index];
  return _selectedDatum.contains(SeriesDatum(series, datum));
}