container/src/main/java/com/streamsets/datacollector/usagestats/UsageTimer.java
public UsageTimer roll() {
    int multiplier;
    synchronized (this) {
      multiplier = getMultiplier();
      changeMultiplier(-multiplier); //stopAll;
    }
    return new UsageTimer().setName(getName()).changeMultiplier(multiplier);
  }
public UsageTimer roll() {
    int multiplier;
    synchronized (this) {
      multiplier = getMultiplier();
      changeMultiplier(-multiplier); //stopAll;
    }
    return new UsageTimer().setName(getName()).changeMultiplier(multiplier);
  }
returns fresh UsageTimer just reset to zero accumulated time