code: private static Object invokeJavaOptionalOf(Object o) {
      try {
        return JAVA_OPTIONAL_OF_METHOD.invoke(null, o);
      } catch (IllegalAccessException e) {
        throw new SecurityException(e);
      } catch (IllegalArgumentException e) {
        throw new IllegalStateException(e);
      } catch (InvocationTargetException e) {
        throw Throwables.propagate(e.getCause());
      }
    }
docs: Invokes java.util.Optional.of.