如何在jmeter中使用beanshell预处理器获得事务控制器的名称

import org.apache.jmeter.control.TransactionController;
import org.apache.jmeter.threads.JMeterContextService;

TransactionController controller = (TransactionController) JMeterContextService.getContext().getCurrentSampler().getProperty("TransactionController").getObjectValue();
String controllerName = controller.getName();
vars.put("controllerName", controllerName);