UpdateMaxMin

New to OxyPlot and OpenSource coding. Have plotted some LineSeries, altered mousing to zoom in and out, but would like the plot to normalize the data being plotted as we zoom in. To do this I need access to MaxY of the data series (see also UpdateMaxMin()). Easy to calculate and implement, but I see that OxyPlot has protected internals offering this already, only I cannot access those from an Example to normalize the data. Is the correct approach to inherit fom a class that implements and exposes this and use my inherited class rather than LineSeries? 2nd, is there a good reason why such integral properies are internal and protected, not public? Sorry if this is a stupid question.