unable to add DateTimeAxis to plot Model

Hi,

I'm trying to add a DateTimeAxis to a PlotModel using the OxyPlot.Wpf.DateTimeAxis and OxyPlot.PlotModel.

I'm getting an error since the DateTimeAxis is not derived from Oxyplot.Axes.Axis:
out of OxyPlot.Wpf Source:

public class DateTimeAxis : Axis

in here Axis is: OxyPlot.Wpf.Axis