Guacamole.Keyboard(document) will cover global window ,event of window can't use it.
Event of Guacamole.Keyboard(selfElement) is invalid ,keyup and keydown can't trigger.
Keybord.reset() is also invalid.
var keyboard = new Guacamole.Keyboard(document); // events can use ,but cover global window object.
var keyboard = new Guacamole.Keyboard(document.getElementById('terminal')); // events can't use.
Guacamole.Keyboard(document) will cover global window ,event of window can't use it. Event of Guacamole.Keyboard(selfElement) is invalid ,keyup and keydown can't trigger. Keybord.reset() is also invalid.