@Override
  public Operator visitTreeDeviceViewScan(
      TreeDeviceViewScanNode node, LocalExecutionPlanContext context) {
    if (node.getDeviceEntries().isEmpty() || node.getTreeDBName() == null) {
      OperatorContext operatorContext =
          context
              .getDriverContext()
              .addOperatorContext(
                  context.getNextOperatorId(),
                  node.getPlanNodeId(),
                  EmptyDataOperator.class.getSimpleName());
      return new EmptyDataOperator(operatorContext);
    }
    throw new IllegalArgumentException("Valid TreeDeviceViewScanNode is not expected here.");
  }
This Visitor is responsible for transferring Table PlanNode Tree to Table Operator Tree.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/planner/TableOperatorGenerator.java