private void resolveAllConflicts(Schema schema) {
        for (Map.Entry<String, List<SDField>> entry : indexToFields.entrySet()) {
            String indexName = entry.getKey();
            List<SDField> fields = entry.getValue();
            if (fields.size() == 1) continue; // It takes two to make a conflict
            resolveConflicts(indexName, fields, schema);
        }
    }
A map from index names to a List of fields going to that index
config-model/src/main/java/com/yahoo/schema/processing/MultifieldIndexHarmonizer.java