@Override
    public N next() {
      if (!hasNext()) {
        throw new NoSuchElementException();
      }
      N result = nextMatchedChild;
      nextMatchedChild = null;
      return result;
    }
The method used for generating the result based on the matched node.
iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/schema/tree/AbstractTreeVisitor.java