public override DockFloatingBay PurgePane(DockPane pane, Point windowLocation, Size windowSize)
        {
            if (_layout.Root == null)
                throw new InvalidOperationException("LayoutEngine.Rootがnullの状態でPurgeすることはできません。");

            var root = (DockBay)_layout.Root.Target;
            return root.PurgePane(pane, windowLocation, windowSize);
        }
        public override DockFloatingBay PurgePane(DockPane pane, Point windowLocation, Size windowSize)
        {
            var bay = new DockFloatingBay();
            bay.Items.Add(pane);
            bay.WindowTop = windowLocation.Y;
            bay.WindowLeft = windowLocation.X;
            bay.WindowWidth = windowSize.Width;
            bay.WindowHeight = windowSize.Height;
            FloatingBays.Add(bay);

            return bay;
        }
 public abstract DockFloatingBay PurgePane(DockPane pane, Point windowLocation, Size windowSize);