declarative pipeline script for UCD deploy publisher in jenkins

Question

`i have created declarative pipeline script in jenkins to build and upload artifacts to Urbancode deploy. But in the "upload to ucd" step its throwing error like :- can not get property 'body' on null object

pipeline{
 agent{
  label "master"
 }
 tools{
  maven "Maven_35ee"
 }
 stages{
   stage("maven build EAR"){
     steps{
        script{
         //////
        }
       }
   }
   stage("upload to nexus"){
     steps{
        //////
       }
   }
 stage("upload to UCD"){
   steps([$class: 'UCDeployPublisher',
        siteName: 'local',
        component: [
            $class: 'com.urbancode.jenkins.plugins.ucdeploy.VersionHelper$VersionBlock',
            componentName: 'Jenkins',
            createComponent: [
                $class: 'com.urbancode.jenkins.plugins.ucdeploy.ComponentHelper$CreateComponentBlock',
                componentTemplate: '',
                componentApplication: 'Jenkins'
            ],
            delivery: [
                $class: 'com.urbancode.jenkins.plugins.ucdeploy.DeliveryHelper$Push',
                pushVersion: '${BUILD_NUMBER}',
                baseDir: "${workspace}/target/",
                fileIncludePatterns: '*.ear',
                fileExcludePatterns: '',
                pushProperties: "",
                pushDescription: 'Pushed from Jenkins'
            ]
        ]
    ])
}
}

`