code: protected void aggregateToBuffer(ClusKernel pointToInsert, long currentTime,
              double negLambda) {
          ClusKernel currentBuffer = this.getBuffer();
          currentBuffer.aggregate(pointToInsert, currentTime - this.timestamp,
                  negLambda);
          this.timestamp = currentTime;
      }
docs: Aggregate the given <code>Kernel</code> to the <code>buffer</code>
  cluster of this entry.
  @param pointToInsert The cluster to aggregate to the buffer.
  @param currentTime The time at which the aggregation occurs.
  @param negLambda A parameter needed to weight the current state of the
  buffer.