code: protected boolean keyReleased (KeyEvent e)
      {
          logKey("keyReleased", e);
  
          // get the info object for this key
          KeyInfo info = _keys.get(e.getKeyCode());
          if (info != null) {
              // remember the last time we received a key release
              info.setReleaseTime(RunAnywhere.getWhen(e));
          }
  
          // notify any key observers of the key release
          notifyObservers(KeyEvent.KEY_RELEASED, e.getKeyCode(), RunAnywhere.getWhen(e));
  
          return (info != null);
      }
docs: Called when Swing notifies us that a key has been released while
  the keyboard manager is active.
  
  @return true to swallow the key event