createSegment method
Creates a segment for a data point in the series.
Implementation
@override
SplineRangeAreaSegment<T, D> createSegment() =>
    SplineRangeAreaSegment<T, D>();Creates a segment for a data point in the series.
@override
SplineRangeAreaSegment<T, D> createSegment() =>
    SplineRangeAreaSegment<T, D>();