@Override
  public MutableClock withZone(ZoneId zone) {
    return new MutableClock(instant, zone, changeAmount);
  }
Initializes a with instant and zone from {@link ZonedDateTime} and 1 second {@link #changeAmount}.
@param zonedDateTime to use for instant and zone information
spock-core/src/main/java/spock/util/time/MutableClock.java