code: private void initTopicTree(HelpTopicNode htnParent, TopicTreeNode ttnParent) {
          initTopicTree(htnParent, ttnParent.getChildren());
          
          if (ttnParent instanceof KeywordTopicTreeNode) {
              initTopicTree(htnParent, ((KeywordTopicTreeNode) ttnParent).getEntries());
          }
      }
docs: Initialize the topic tree. Converts the Oracle help TopicTreeNode-based tree to a
  HelpTopicNode-based tree.
  
  @param htnParent Current help topic node.
  @param ttnParent Current topic tree node.