public abstract void beforeMutate(Describable displayName);

    public abstract ValueSupplier.ValueConsumer forUpstream(ValueSupplier.ValueConsumer consumer);

    public boolean isFinalized() {
        return this == FINALIZED_VALUE;
    }

    /**
     * Is this state final or on its way for being finalized?
     */

    }

    private void finalizeNow(EvaluationContext.ScopeContext context, ValueConsumer consumer) {
        try {
            value = finalValue(context, value, state.forUpstream(consumer));
        } catch (Exception e) {
            if (displayName != null) {
                throw new PropertyQueryException(String.format("Failed to calculate the value of %s.", displayName), e);