public void addChild(final PathPatternNode<V, S> tmpNode) {
    final String nodeName = tmpNode.getName();
    if (PathPatternUtil.hasWildcard(nodeName)
        && !PathPatternUtil.isMultiLevelMatchWildcard(nodeName)
        && !ONE_LEVEL_PATH_WILDCARD.equals(nodeName)) {
      childrenNamesWithNonTrivialWildcard.add(nodeName);
    }
    children.put(nodeName, tmpNode);
  }
Used only in PatternTreeMap to identify whether from root to the current node is a registered
path pattern. In PatternTreeMap, it can be replaced by the size of the valueSet
iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/path/PathPatternNode.java