createRenderer method
Create the hilo open close series renderer.
Implementation
@override
HiloOpenCloseSeriesRenderer<T, D> createRenderer() {
  HiloOpenCloseSeriesRenderer<T, D> seriesRenderer;
  if (onCreateRenderer != null) {
    seriesRenderer =
        onCreateRenderer!(this) as HiloOpenCloseSeriesRenderer<T, D>;
    return seriesRenderer;
  }
  return HiloOpenCloseSeriesRenderer<T, D>();
}