code: @Override
      protected long overallEndTime() {
          long ret = super.overallEndTime();
  
          for (Node child : nodes) {
              long childEndTime = child.overallEndTime();
  
              if (childEndTime > ret) {
                  ret = childEndTime;
              }
          }
  
          return ret;
      }
docs: This method determines the overall end time of this node.
  
  @return The overall end time