* `App.run_after_keychord(chord)` -- mimics keystrokes resulting in `chord`
  and then draws one frame.

* `App.run_after_keychord(chord, key)` -- mimics the final `key` press
  resulting in `chord` and then draws one frame.

function App.run_after_keychord(chord)
  App.keychord_press(chord)
  App.keyreleased(chord)

function App.run_after_keychord(chord, key)
  App.keychord_press(chord, key)
  App.keyreleased(key)