public Long getExpires() {
        return expires;
    }
Returns the time after which the data stored in this object is invalid
and must not be used. The time returned is a UNIX-style epoch timestamp
whose value is the number of milliseconds since midnight of January 1,
1970 UTC. If this object does not expire, null is returned.

@return
    The time after which the data stored in this object is invalid and
    must not be used, or null if this object does not expire.
extensions/guacamole-auth-json/src/main/java/org/apache/guacamole/auth/json/user/UserData.java