Duration lap() {
    Instant now = clock.instant();
    Duration duration = Duration.between(lapStartTime, now);
    lapStartTime = now;
    return duration;
  }
Captures the time since last lap or creation, and resets the start time.

@return the duration of the last lap, or since creation
jib-core/src/main/java/com/google/cloud/tools/jib/builder/Timer.java