title: how do i get notified from buddy image change Xmpp android
body: <p>I am trying to develop an Xmpp client and displaying buddylist with images.I am storing images in cache directory for quick retrieval and unnesscary network usuage.The problem here is if the buddy has changed his image  how do i get notified to fetch the new image from the server ,not from the local cache. 
  Please suggest.</p>
  
  <p>Im using asmack api.</p>