@Override
        public V get(Object key) {
            if (key instanceof String && originals.containsKey(key)) {
                // Intentionally ignore the result; call just to mark the original entry as used
                originals.get(key);
            }
            // But always use the resolved entry
            return super.get(key);
        }
ResolvingMap keeps a track of the original map instance and the resolved configs.
The originals are tracked in a separate nested map and may be a `RecordingMap`; thus
any access to a value for a key needs to be recorded on the originals map.
The resolved configs are kept in the inherited map and are therefore mutable, though any
mutations are not applied to the originals.
clients/src/main/java/org/apache/kafka/common/config/AbstractConfig.java