title: How to add to existing properties in groovy script?
body: <p>I have a dsl file in which properties such as log rotator and parameters are being defined for a jenkins job. However, I want to add a property to the jenkins job in a groovy script. I do this by putting 
  <code>properties([pipelineTriggers([githubPush()])])</code>
  in the corresponding groovy script. However, this overwrites all other parameters and properties as defined in the dsl script. </p>
  
  <p>What I have right now is putting all properties in the dsl script in the groovy script as well but that causes two different places where developers need to change the properties. Is there a way in groovy to simply add a new property instead of overwriting the old ones. </p>
  
  <p>Something like
  <code>properties.add([pipelineTriggers([githubPush()])])</code>
  would be very helpful.</p>