title: Jenkins Pipeline Access stage steps variable in power shell execution
body: <p>I want to access normal variable defined in my steps into power shell execution.
  We can access environment variables using $env but, how to access normal step variables?</p>
  
  <pre><code>stages {
          stage ('sometask') {
                  steps{
                       script {
                          def someString = 'Hi'
                          withCredentials(...) {
                          def out = powershell(returnStdout: true, script: 
                                 '''
                                 // Access someString 
                           ''')
                           println out
                         }
                  }
           }
  }
  </code></pre>