title: How can i use 'parallel' option in jenkins pipeline in the 'post' section?
body: <p>I looked at many pipeline examples and how to write the post build section in a pipeline script. But never got my answer i was looking for.
  I have 4 jobs - say Job A,B,C and D. I want job A to run first, and if successful it should trigger Job B,C,D in parallel. If Job A fails, it should trigger only Job B. Something like below:</p>
  
  <pre><code>pipeline {
      agent any
  
  stages {
      stage('Build_1') {
          steps {
              sh '''
                 Build Job A
              '''
          }
      }
  
  post {
      failure {
          sh '''
              Build Job B
          '''
      }
      success {
           sh '''
               Build Job B,C,D in parallel
           '''
      }
  }
  }
  </code></pre>
  
  <p>I tried using 'parallel' option in post section but it gave me errors. Is there a way to build Job B,C,D in parallel, in the post 'success' section?</p>
  
  <p>Thanks in advance!</p>