question: private XYDataset createDataset1 ( ) { XYSeries series1 = new XYSeries ( "Series 1" ) ; series1 . add ( 10.0 , 12353.3 ) ; series1 . add ( 20.0 , 13734.4 ) ; series1 . add ( 30.0 , 14525.3 ) ; series1 . add ( 40.0 , 13984.3 ) ; series1 . add ( 50.0 , 12999.4 ) ; series1 . add ( 60.0 , 14274.3 ) ; series1 . add ( 70.0 , 15943.5 ) ; series1 . add ( 80.0 , 14845.3 ) ; series1 . add ( 90.0 , 14645.4 ) ; series1 . add ( 100.0 , 16234.6 ) ; series1 . add ( 110.0 , 17232.3 ) ; series1 . add ( 120.0 , 14232.2 ) ; series1 . add ( 130.0 , 13102.2 ) ; series1 . add ( 140.0 , 14230.2 ) ; series1 . add ( 150.0 , 11235.2 ) ; XYSeries series2 = new XYSeries ( "Series 2" ) ; series2 . add ( 10.0 , 15000.3 ) ; series2 . add ( 20.0 , 11000.4 ) ; series2 . add ( 30.0 , 17000.3 ) ; series2 . add ( 40.0 , 15000.3 ) ; series2 . add ( 50.0 , 14000.4 ) ; series2 . add ( 60.0 , 12000.3 ) ; series2 . add ( 70.0 , 11000.5 ) ; series2 . add ( 80.0 , 12000.3 ) ; series2 . add ( 90.0 , 13000.4 ) ; series2 . add ( 100.0 , 12000.6 ) ; series2 . add ( 110.0 , 13000.3 ) ; series2 . add ( 120.0 , 17000.2 ) ; series2 . add ( 130.0 , 18000.2 ) ; series2 . add ( 140.0 , 16000.2 ) ; series2 . add ( 150.0 , 17000.2 ) ; XYSeriesCollection collection = new XYSeriesCollection ( ) ; collection . addSeries ( series1 ) ; collection . addSeries ( series2 ) ; return collection ; }
target:  Creates a sample dataset.