title: How can I change value from a node when having a server instance (node-opcua)
body: <p>I'm using node-opcua library. I have instance of OPCUAServer. How can I get node value and edit it?  </p>
  
  <p>I assume OPC client should be able to do it, but I want to interact with OPC server since I'm responding to an internal event.  </p>
  
  <p>Should I maybe use something like <a href="http://node-opcua.github.io/api_doc/0.2.0/files/packages_node-opcua-service-write__generated___auto_generated_WriteRequest.js.html" rel="nofollow noreferrer">WriteRequest</a> to perform such operation?</p>