code: public void purgeDeviceList()
              throws SmackException.NotLoggedInException, InterruptedException, XMPPException.XMPPErrorException,
              SmackException.NotConnectedException, SmackException.NoResponseException {
          synchronized (LOCK) {
              getOmemoService().purgeDeviceList(new LoggedInOmemoManager(this));
          }
      }
docs: Publish a new device list with just our own deviceId in it.
  
  @throws SmackException.NotLoggedInException
  @throws InterruptedException
  @throws XMPPException.XMPPErrorException
  @throws SmackException.NotConnectedException
  @throws SmackException.NoResponseException