code: private static <U, T extends TimePoint<U, T>> T add(
          TimePoint<U, T> context,
          ChronoElement<?> element,
          boolean forward
      ) {
  
          U unit = context.getChronology().getBaseUnit(element);
  
          if (forward) {
              return context.plus(1, unit);
          } else {
              return context.minus(1, unit);
          }
  
      }
docs: wildcard capture