static <T> BuilderRef<Set<T>> forUnorderedSet() {
        return new DefaultBuilderRef<>(HashSet::new,
                HashSet::new,
                Collections::unmodifiableSet,
                Collections::emptySet);
    }
Creates a builder reference to an unordered set.

@param <T> Type of value in the set.
@return Returns the created set.
smithy-utils/src/main/java/software/amazon/smithy/utils/BuilderRef.java