Run multiple containers using Jenkins with declarative pipeline syntax

Jenkinsfile

pipeline {
    agent none
    stages {
        stage('unit-testing') {
            agent {
                docker { image 'node:8.15.1-jessie' }
            }
            steps {
                sh 'node -v'
            }
        }
        stage('pr-build') {
            agent {
                docker { image 'node:6.17.0-jessie' }
            }
            steps {
                sh 'node --version'
            }
        }
    }
}