title: How to make selectable option in OPC-UA?
body: <p>Assuming having a read/write variable called Fruit.
  Selectable options are Apple, Pear, Strawberry &amp; Pineapple.</p>
  <p>Using <a href="https://reference.opcfoundation.org/v104/Core/docs/Part5/7.17/" rel="nofollow noreferrer">OptionSetType</a> seems to be the most suiteable way.
  But I did not find any examples for <a href="https://node-opcua.github.io/api_doc/2.0.0/classes/optionset.html" rel="nofollow noreferrer">node-opcua</a></p>
  <p>Can somebody provide an example or is there another/better/smarter way?</p>