ChartSeries.getSelectedPointCount Method
        
 Gets the number of data points within this series or one of its groupings that are individually selected.
 
         
        Parameters
        
            - groupingIndex
            
 
            - 
                
Type: Number (Integer)
The index of the grouping within this series
 for which to return the count, or omit for all selected data points of this series.
Optional: True 
        
        Return Value
        
Type: Number (Integer)