title: Jenkins plugin development - environment variables
body: <p>Is there any possibility to get a map of environment variables that are used in Jenkins?
  I am trying to develop my own plugin and need to access the variable BUILD_USER_ID, which is provided by the build user vars plugin.</p>
  
  <p>There is a class called EnvVars, which inherits from TreeMap, but it is obviously empty, if you create an object of this.</p>
  
  <pre><code>EnvVars env = new EnvVars();
  </code></pre>
  
  <p>Where are these variables stored , so that I can get them and use them in my plugin?</p>