Vertical line on QChartView

[neo_qt]

I have a QChartView containing several series and I would like to add two vertical lines.

Here is the sample code.
I guess that since the x point is the same, it won't display. Is there a workaround ?

QChart *chart = new QChart();

// Adding some series
chart->addSeries(Series1);
chart->addSeries(Series2);
// Series1 and Series2 display properly

// Trying to add one vertical line
QLineSeries* VerticalSeries = new QLineSeries();
VerticalSeries ->append(1.0, -10.0);
VerticalSeries ->append(1.0, 10.0);

chart->addSeries(VerticalSeries);