code: protected void aggregateCluster(ClusKernel otherData, long currentTime,
              double negLambda) {
          this.getData().aggregate(otherData, currentTime - this.timestamp,
                  negLambda);
          this.timestamp = currentTime;
      }
docs: Aggregate the given <code>Kernel</code> to the <code>data</code> cluster
  of this entry.
  @param otherData The <code>Entry</code> to be aggregated.
  @see #data
  @see Kernel