How to use the igniteui-angular-charts/ES5/igx-line-series-component.IgxLineSeriesComponent function in igniteui-angular-charts

this.chart.series.clear();
            this.chart.series.add(series1);
            this.chart.series.add(series2);

        } else if (seriesType === "Line") {

            const series1 = new IgxLineSeriesComponent();
            series1.name = "series1";
            series1.markerType = MarkerType.Circle;
            series1.valueMemberPath = "USA";
            series1.title = "USA";
            series1.xAxis = this.xAxis;
            series1.yAxis = this.yAxis;
            series1.thickness = 2;

            const series2 = new IgxLineSeriesComponent();
            series1.name = "series1";
            series2.markerType = MarkerType.Circle;
            series2.valueMemberPath = "RUS";
            series2.title = "Russia";
            series2.xAxis = this.xAxis;
            series2.yAxis = this.yAxis;
            series2.thickness = 2;

            this.chart.series.clear();
            this.chart.series.add(series1);
            this.chart.series.add(series2);

        } else if (seriesType === "Point") {

            const series1 = new IgxPointSeriesComponent();
            series1.name = "series1";

series1.yAxis = this.yAxis;

            const series2 = new IgxColumnSeriesComponent();
            series2.name = "series2";
            series2.valueMemberPath = "RUS";
            series2.title = "Russia";
            series2.xAxis = this.xAxis;
            series2.yAxis = this.yAxis;

            this.chart.series.clear();
            this.chart.series.add(series1);
            this.chart.series.add(series2);

        } else if (seriesType === "Line") {

            const series1 = new IgxLineSeriesComponent();
            series1.name = "series1";
            series1.markerType = MarkerType.Circle;
            series1.valueMemberPath = "USA";
            series1.title = "USA";
            series1.xAxis = this.xAxis;
            series1.yAxis = this.yAxis;
            series1.thickness = 2;

            const series2 = new IgxLineSeriesComponent();
            series1.name = "series1";
            series2.markerType = MarkerType.Circle;
            series2.valueMemberPath = "RUS";
            series2.title = "Russia";
            series2.xAxis = this.xAxis;
            series2.yAxis = this.yAxis;
            series2.thickness = 2;