docs: protected void makeOlder(long currentTime, double negLambda) {
  //        assert (currentTime > this.timestamp) : "currentTime : "
  //                + currentTime + ", this.timestamp: " + this.timestamp;
  
          long diff = currentTime - this.timestamp;
          this.buffer.makeOlder(diff, negLambda);
          this.data.makeOlder(diff, negLambda);
          this.timestamp = currentTime;
      }