@Override
    public final BooleanProperty booleanPropertyOf(String key, BooleanSupplier ifEmpty) {
        return (BooleanProperty) properties.computeIfAbsent(key, k -> prepare(k, new SimpleBooleanProperty(), ifEmpty.getAsBoolean()));
    }
{@inheritDoc}
@deprecated Not supported for observables
tool-parent/tool-config/src/main/java/com/speedment/tool/config/AbstractDocumentProperty.java