@Override
        public boolean equals(Object obj) {
            if (!(obj instanceof Arc)) {
                return false;
            }
            Arc other = (Arc) obj;
            return Objects.equals(from, other.from) && Objects.equals(to, other.to);
        }
Retrieve resulting name of a dimension after solving for constraints, or empty if no
solution is found yet, or this dimension was not added before finding a solution.
model-integration/src/main/java/ai/vespa/rankingexpression/importer/DimensionRenamer.java