@Override
    @Deprecated
    public <VR> KStream<K, VR> transformValues(final ValueTransformerSupplier<? super V, ? extends VR> valueTransformerSupplier,
                                               final Named named,
                                               final String... stateStoreNames) {
        Objects.requireNonNull(valueTransformerSupplier, "valueTransformerSupplier can't be null");
        Objects.requireNonNull(named, "named can't be null");
        return doTransformValues(
            toValueTransformerWithKeySupplier(valueTransformerSupplier),
            new NamedInternal(named),
            stateStoreNames);
    }
Repartition a stream. This is required on join operations occurring after
an operation that changes the key, i.e, selectKey, map(..), flatMap(..).
streams/src/main/java/org/apache/kafka/streams/kstream/internals/KStreamImpl.java