* Creates a Type-3 message using default values from the current
     * environment.
     */
    public Type3Message() {
        setFlags(getDefaultFlags());
        setDomain(getDefaultDomain());
        setUser(getDefaultUser());
        setWorkstation(getDefaultWorkstation());
    }

    /**
     * Creates a Type-3 message in response to the given Type-2 message
     * using default values from the current environment.
     *