else { if (Log.isDebugEnabled()) { if (!id.startsWith("SIP/")) { Log.debug("Cannot destroy non-existent CallSession with id: " + id); } } }
    public synchronized CallSession destroyPhoneSession(String id) {        CallSession session = sessionMap.remove(id);        if (session != null) {            try {                Collection<CallSession> sessions = userSessionMap.get(session.getUsername());                // should never be null                sessions.remove(session);                // Remove the map if there are nolonger any session for this user                if (sessions.size() == 0) {                    userSessionMap.remove(session.getUsername());                }            }            catch (RuntimeException e) {                Log.error("CallSessionFactory: Unexpected RuntimeException occurred ", e);            }        }        return session;    }