public <T extends PlanNode> List<T> findAll() {
    ImmutableList.Builder<T> nodes = ImmutableList.builder();
    findAllRecursive(node, nodes);
    return nodes.build();
  }
Return a list of matching nodes ordered as in pre-order traversal of the plan tree.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/relational/planner/PlanNodeSearcher.java