def add_keyboard_event_listeners
      Element.find("html").on :keydown do |event|
        @keys[get_key_id(event)] = true
      end
      Element.find("html").on :keyup do |event|
        @keys[get_key_id(event)] = false
      end
      ::Window.on :blur do |event|
        @keys.fill false
      end
    end
def add_keyboard_event_listeners
      Element.find("html").on :keydown do |event|
        @keys[get_key_id(event)] = true
      end
      Element.find("html").on :keyup do |event|
        @keys[get_key_id(event)] = false
      end
      ::Window.on :blur do |event|
        @keys.fill false
      end
    end
adds keyboard event listeners to entire page