## 🐛 Bug Report

Running with java binding and Firefox, the framework occasionally throws NullPointerException on the isDisplayed call.

**Please see https://github.com/mozilla/geckodriver/issues/1825 for more information.** As stated from geckodriver team, the issue is apparently related to the custom JS that is executed with this method. The ticket also contains trace logs. 

## To Reproduce

Hard to provide steps, as it happens "randomly".

## Expected behavior

Should not throw exception..

## Environment

OS: Windows 10
Browser: Firefox
Browser version: 84.0.1
Browser Driver version: geckodriver 0.28.0 (c00d2b6acd3f 2020-11-03 16:29 +0200)
Language Bindings version: java 3.141.59

int y = ((Number) rawRect.get("y")).intValue();
    int width = ((Number) rawRect.get("width")).intValue();
    int height = ((Number) rawRect.get("height")).intValue();
    return new Rectangle(x, y, height, width);
  }
  @Override
  public Coordinates getCoordinates() {
    return new Coordinates() {
      @Override
      public Point onScreen() {
        throw new UnsupportedOperationException("Not supported yet.");
      }
      @Override
      public Point inViewPort() {
        Response response = execute(DriverCommand.GET_ELEMENT_LOCATION_ONCE_SCROLLED_INTO_VIEW(getId()));
        @SuppressWarnings("unchecked")
        Map<String, Number> mapped = (Map<String, Number>) response.getValue();
        return new Point(mapped.get("x").intValue(), mapped.get("y").intValue());
      }
      @Override
      public Point onPage() {
        return getLocation();
      }
      @Override
      public Object getAuxiliary() {
        return getId();
      }
    };
  }
  @Override