}

        public Class<? extends ValueSource<T, P>> getValueSourceType() {
            return value.sourceType;
        }

        @Override
        protected String toStringNoReentrance() {
            return String.format("valueof(%s)", getValueSourceType().getSimpleName());
        }

        @Nullable
        public Class<P> getParametersType() {
            return value.parametersType;

     */
    protected abstract String describeContents();

    // This method is final - implement describeContents() instead
    @Override
    protected final String toStringNoReentrance() {
        if (displayName != null) {
            return displayName.toString();
        } else {
            return describeContents();
        }
    }

    @Override

        @Override
        public boolean calculatePresence(ValueConsumer consumer) {
            return findDomainObject(getName()) != null;
        }

        @Override
        protected String toStringNoReentrance() {
            return String.format("provider(%s '%s', %s)", getTypeDisplayName(), getName(), getType());
        }
    }