private static boolean hasHnswIndex(ImmutableSDField field) {
        return field.getAttributes().values().stream()
                .anyMatch(a -> a.hnswIndexParams().isPresent());
    }
Validates hnsw settings and warns if using hnsw and having searchable copies > 1 for a content cluster

@author hmusum
config-model/src/main/java/com/yahoo/vespa/model/application/validation/HnswValidator.java