title: var userProperties = PropertiesService.getUserProperties(); is not working properly for me?
body: <p>I am creating userproperties with   PropertiesService, as</p>
  
  <pre><code>      var userProperties = PropertiesService.getUserProperties();
  </code></pre>
  
  <p>for storing users single token for my add-on , When i set usertoken in userproperties with a key pair value as,   userProperties.setProperty('USERTOKEN','token');    in an document.</p>
  
  <p>Once i do this as per the userproperties scope i can retrieve the user properties value from any of the document  by using  userProperties.getProperty('USERTOKEN'); but,</p>
  
  <p>When i do that the value is null (i.e), i cant retrieve the  'userProperties' value from other documents,</p>
  
  <p>So that, the scope of the userproperties fails. The userproperties value is associated only with the particular document where  it's created.</p>
  
  <p>once my add-on is installed i used to check every time userproperties  value   for all documents ,</p>
  
  <pre><code>        if(value)
           {
            retrieve data;
            }
               else
               {
                authorize;
  
                 }
  </code></pre>
  
  <p>Thus value is null  and the user is made to authorize everytime for every new document.   Since my add-on cant retrieve  the value from userProperties.getProperty('USERTOKEN');</p>