* {@link ValueListener#valueObtained(ValueListener.ObtainedValue, ValueSource)}.
     */
    @EventScope(Scope.Build.class)
    interface ComputationListener {
        void beforeValueObtained();

        void afterValueObtained();
    }

    @EventScope(Scope.Build.class)
    interface ValueListener {
        <T, P extends ValueSourceParameters> void valueObtained(