title: Multi Value option in Apache Nifi Processor
body: <p>I was designing on my own custom processor. I added couple of simple property descriptor into it with simple non-empty validators. I was looking for a validator by which I can add multiple values into one property descriptor. Something like below.</p>
  
  <p><a href="https://i.stack.imgur.com/3qtwQ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/3qtwQ.png" alt="enter image description here"></a></p>
  
  <p>My property descriptor will have multi value selection option.</p>
  
  <p>Does anyone know how can I achieve it ?</p>