code: @Override
      public void addActionPressed(Integer key, EventAction action)
      {
          final List<EventAction> list;
          if (actionsPressed.get(key) == null)
          {
              list = new ArrayList<>();
              actionsPressed.put(key, list);
          }
          else
          {
              list = actionsPressed.get(key);
          }
          list.add(action);
      }
docs: /*
  Keyboard