我在Jenkinsfile中有一个步骤，看起来像这样：

steps {
        sh '''#!/bin/bash
              docker kill $(docker ps -q --filter ancestor=nginx-example )'''
        sh '''docker build -t nginx-example .
              docker run -d -p 8081:80 nginx-example'''
      }

而像这样的错误

"docker kill" requires at least 1 argument.
See 'docker kill --help'.

Usage:  docker kill [OPTIONS] CONTAINER [CONTAINER...]

Kill one or more running containers
[Pipeline] }
[Pipeline] // stage
[Pipeline] }
[Pipeline] // node
[Pipeline] End of Pipeline
ERROR: script returned exit code 1
Finished: FAILURE

我怎么能用$（）运行docker kill呢？它只在Jenkinsfile中不起作用，而在Jenkins Pipeline中它完全工作正常。