docs: protected void recalculateData() {
          Node currentChild = this.getChild();
          if (currentChild != null) {
              ClusKernel currentData = this.getData();
              currentData.clear();
              Entry[] entries = currentChild.getEntries();
              for (int i = 0; i < entries.length; i++) {
                  currentData.add(entries[i].getData());
              }
          } else {
              this.clear();
          }
      }