private void UpdateBreakpoints()
        {
            if (Repository == null)
            {
                return;
            }
            var bps = Repository.All <Breakpoint>();

            Breakpoints = bps.ToList();
            if (BreakpointsList == null)
            {
                BreakpointsList = new TreeViewModel();
            }
            BreakpointsList.SingleItemIcon = "BreakpointIcon";
            BreakpointsList.Data           = Breakpoints.OfType <IItem>().ToList();
            BreakpointsList.Submit         = i =>
            {
                var bp = i as Breakpoint;
                if (bp != null)
                {
                    Execute(new NavigateToNodeCommand()
                    {
                        Node   = bp.Action,
                        Select = true
                    });
                }
            };
        }