code: public <X> X getScreenshotAs(OutputType<X> target) throws WebDriverException {
      OperaWebElement body = (OperaWebElement) findElementByCssSelector(":root");
      return target.convertFromPngBytes(body.captureScreen().getPng());
    }
docs: TODO: CORE-39436 areas outside of the current viewport is black, this is a problem with Opera not OperaDriver