title: Is there any way to check if oauth token is expired or not?
body: <p>I am accessing web api using oauth token.</p>
  
  <p>Token expires after <code>1 hour</code>. But I want to add functionality to generate new token when it expires.</p>
  
  <p>I found that in case of expired token it sends StatusCode as <code>unauthorized</code>.</p>
  
  <p>Please let me know if its the only statuscode which tells about expiration of token.</p>