[refactorMouseDispatcher] using instanceOf assert
[refactorMouseDispatcher] using instanceOf assert

danmane/plottable,NextTuesday/plottable,palantir/plottable,danmane/plottable,NextTuesday/plottable,NextTuesday/plottable,iobeam/plottable,softwords/plottable,palantir/plottable,palantir/plottable,danmane/plottable,iobeam/plottable,softwords/plottable,palantir/plottable,iobeam/plottable,softwords/plottable