Can't find any good example with how to: use MMFPile

[xpandsoftware]

documentation/examples/videos - all talking about advantages, but where is simple working examples?
i have tried to use this... unfortunately it doesn't work for me:

    DefaultPileBase xPile = null;
            if (!useMemoryFilePile) xPile = new DefaultPile();
            else
            {
                var ipile = (xPile = new MMFPile(null)) as MMFPile;
                if (!System.IO.Directory.Exists(DataDirectory.Value)) System.IO.Directory.CreateDirectory(DataDirectory.Value);
                ipile.DataDirectoryRoot = DataDirectory.Value;
            }

then, when i am trying to check list of objects in xPile:
xPile.FirstOrDefault(e => e.Valid) <= null reference exception

sorry, just have found what is going wrong, "Configure" & "Start" methods have to be executed.

[itadapter]

https://github.com/aumcode/nfx/tree/master/Source/NFX/ApplicationModel/Pile

https://github.com/aumcode/nfx/blob/master/Source/Testing/Manual/WinFormsTest/PileForm.cs#L170

also, this repository is stale.
Use new https://github.com/agnicore/nfx