how to split a LineString into two LineStrings

[Milad0071]

maptalks's version and what browser you use?

maptalks v0.37.0
Google Chrome
Issue description

I need two split a existed LineString, into Two Line Strings from where the user right clicks and choose the split option. I wonder if there is way for it. Any help would be appreciated. Thank you.
this is my function for split:
this.splitLineString = function (coordinate, target) { new maptalks.Marker( coordinate, { 'symbol': { 'markerType': 'ellipse', 'markerFill': '#ffffff', 'markerLineColor': '#e65100', 'markerLineWidth': 3, 'markerWidth': 5, 'markerHeight': 5 }, } ).addTo(draw_layer); console.log(target) }
and this is the code which makes the LineString:
`if (param.geometry.type === 'LineString' && FreeLineMode === true) {

            var GisSymbol = param.target.options.symbol.tag.GisSymbol;

            var dg = drawTool.getCurrentGeometry();
            if (dg != null) {
                line = new maptalks.LineString(
                    dg.getCoordinates(),
                    {
                        tag: {
                            GisSymbolId: GisSymbol.GisSymbolId,
                            GisInfoGuid: guid(),
                            GisInfoId: null,
                            GisSymbolSeqNum: GisSymbol.GisSymbolSeqNum,
                            IsNew: true,
                            Element: GisSymbol,
                            Label: null
                        },
                        symbol: {

                            'lineColor': 'red',
                            'lineWidth': 2,
                            'lineJoin': 'round',
                            'lineCap': 'round',
                            //'lineDasharray': lineDasharray,
                            //'lineOpacity': {
                            //    stops: [[GisSymbol.GisSymbolZoomStart, 0], [GisSymbol.GisSymbolZoomStop, 1]]
                            //},
                            'textPlacement': 'line',
                            'textSize': 12,
                            'textDy': -20,
                            'textFaceName': 'sans-serif',
                            //'textName':  "" + element.ItemLength + " m",
                            'textWeight': 'normal',
                            'textStyle': 'normal',
                            'textFill': '#000',
                            //'textOpacity': { stops: [[GisSymbol.GisSymbolZoomStart, 0], [GisSymbol.GisSymbolZoomStop, 1]] },
                            'textHaloFill': '#fff',
                            //'textOpacity': { stops: [[GisSymbol.GisSymbolZoomStart, 0], [GisSymbol.GisSymbolZoomStop, 1]] },
                            'textWrapCharacter': '\n',
                            'textLineSpacing': 0,
                            'textHorizontalAlignment': 'middle',
                            'textVerticalAlignment': 'middle',
                            'textAlign': 'center'
                        },

                    }
                );
                draw_line_layer.addGeometry(line);
            }


        }`