public void setChangeAmount(TemporalAmount changeAmount) {
    this.changeAmount = Objects.requireNonNull(changeAmount, "changeAmount may not be null");
  }
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