2 Line Label with Tail Truncation

I'm converting a MonoTouch.Dialog app to Xamarin.Forms.

I have a Cell in a ListView and that has a "Detail" line that should be 2 lines long, and should truncate the tail after that.

        var lblDetail = new Label
        {
            LineBreakMode = LineBreakMode.TailTruncation,
            Text = "a really long string that should show 2 lines then ..."
        };

How do I set something like, "Lines = 2"