A collection that stores the Sparkline objects for the specified sparkline group.
Use the SparklineGroup.Sparklines property to obtain the SparklineCollection collection for the specified sparkline group.
Use the SparklineCollection.Add method to create a new sparkline and add it to the existing sparkline group.
To access an individual Sparkline object in a group, use the indexer notation. The index number specifies the order in which the sparklines are added to the sparkline group.