@Override
  public Operator visitSchemaQueryOrderByHeat(
      SchemaQueryOrderByHeatNode node, LocalExecutionPlanContext context) {
    List<Operator> children =
        node.getChildren().stream().map(n -> n.accept(this, context)).collect(Collectors.toList());

    OperatorContext operatorContext =
        context
            .getDriverContext()
            .addOperatorContext(
                context.getNextOperatorId(),
                node.getPlanNodeId(),
                SchemaQueryOrderByHeatOperator.class.getSimpleName());

    return new SchemaQueryOrderByHeatOperator(operatorContext, children);
  }
This Visitor is responsible for transferring PlanNode Tree to Operator Tree.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/planner/OperatorTreeGenerator.java