@Override
        public V get(Object key) {
            if (key instanceof String) {
                String stringKey = (String) key;
                String keyWithPrefix;
                if (prefix.isEmpty()) {
                    keyWithPrefix = stringKey;
                } else {
                    keyWithPrefix = prefix + stringKey;
                }
                ignore(keyWithPrefix);
                if (withIgnoreFallback)
                    ignore(stringKey);
            }
            return super.get(key);
        }
Marks keys retrieved via `get` as used. This is needed because `Configurable.configure` takes a `Map` instead
of an `AbstractConfig` and we can't change that without breaking public API like `Partitioner`.
clients/src/main/java/org/apache/kafka/common/config/AbstractConfig.java