if ( firstKey == 0 ) {
                firstKey = k;
            }

            if ( timeout > 0 ) {
                curResp.setExpiration(System.currentTimeMillis() + timeout);
            }
            else {
                curResp.setExpiration(null);
            }

            curResp.setMid(k);
            this.response_map.put(k, curResp);

            Request next = curReq.getNext();

                        log.trace("Not found " + link);
                    }
                    break;
                }
            }
        }

        if ( dr != null && now > dr.getExpiration() ) {
            if ( log.isTraceEnabled() ) {
                log.trace("Expiring links " + link);
            }
            links.map.remove(link);
            dr = null;
        }

     * @return this session's UID
     */
    public int getUid () {
        return this.uid;
    }


    /**
     * @return this session's expiration time
     */
    public Long getExpiration () {
        return this.expiration > 0 ? this.expiration : null;
    }


    /**
     * @return this session's credentials
     */
    public CredentialsInternal getCredentials () {