I’m using the Apache POI library 5.2.3 in Scala to create a line chart in a PowerPoint presentation.

// createData returns XDDFChartData
var chartData = chart.createData(
    ChartTypes.LINE,
    bottomAxis,
    leftAxis
).asInstanceOf[XDDFLineChartData]

// addSeries returns XDDFChartData.Series
var series = chartData.addSeries(bottomAxisDataSource, seriesDataSource)
series.setSmooth(false)

error: value setSmooth is not a member of org.apache.poi.xddf.usermodel.chart.XDDFChartData.Series

However I need series to be of type XDDFLineChartData.Series not XDDFChartData.Series so I can access the setSmooth() method. How do I cast to the inner member type Series here?

The following attempt fails

chartData.addSeries(bottomAxisDataSource, seriesDataSource).asInstanceOf[XDDFLineChartData.Series]

with

error: type Series is not a member of object org.apache.poi.xddf.usermodel.chart.XDDFLineChartData