function drawSeriesLines(series, ctx, plotOffset, plotWidth, plotHeight, drawSymbol, getColorOrGradient) {
            ctx.save();
            ctx.translate(plotOffset.left, plotOffset.top);
            ctx.lineJoin = "round";

            if (series.lines.dashes && ctx.setLineDash) {
                ctx.setLineDash(series.lines.dashes);
            }

            var datapoints = {
                format: series.datapoints.format,
                points: series.datapoints.points,
                pointsize: series.datapoints.pointsize
            };

            if (series.decimate) {
                datapoints.points = series.decimate(series, series.xaxis.min, series.xaxis.max, plotWidth, series.yaxis.min, series.yaxis.max, plotHeight);
            }

            var lw = series.lines.lineWidth;

            ctx.lineWidth = lw;
            ctx.strokeStyle = series.color;
            var fillStyle = getFillStyle(series.lines, series.color, 0, plotHeight, getColorOrGradient);
            if (fillStyle) {
                ctx.fillStyle = fillStyle;
                plotLineArea(datapoints, series.xaxis, series.yaxis, series.lines.fillTowards || 0, ctx, series.lines.steps);
            }

            if (lw > 0) {
                plotLine(datapoints, 0, 0, series.xaxis, series.yaxis, ctx, series.lines.steps);
            }

            ctx.restore();
        }
- drawSeriesLines(series, ctx, plotOffset, plotWidth, plotHeight, drawSymbol, getColorOrGradient)

         This function is used for drawing lines or area fill.  In case the series has line decimation function
         attached, before starting to draw, as an optimization the points will first be decimated.

         The series parameter contains the series to be drawn on ctx context. The plotOffset, plotWidth and
         plotHeight are the corresponding parameters of flot used to determine the drawing surface.
         The function getColorOrGradient is used to compute the fill style of lines and area.