public class StreamsConfig {     
    public static final String DEFAULT_STORE_IMPLEMENTATION_CLASS_CONFIG = "default.store.impl.class";
    private static final String DEFAULT_STORE_IMPLEMENTATION_CLASS_DOC = "Store supplier implementation class to use. Default is set as RocksDBStoreImplementation. It can be overwritten dynamically during streaming operation.";                


	.define(DEFAULT_STORE_IMPLEMENTATION_CLASS_CONFIG,
            Type.CLASS,
            RocksDBStoreImplementation.class.getName(),
            Importance.MEDIUM,
            DEFAULT_STORE_IMPLEMENTATION_CLASS_DOC) 
}

	/**
     * Materialize a {@link StateStore} with the store implementation.
     *
     * @param storeImplementation  store implementation used to materialize the store
     * alphanumerics, '.', '_' and '-'.
     * @param <K>       key type of the store
     * @param <V>       value type of the store
     * @param <S>       type of the {@link StateStore}
     * @return a new {@link Materialized} instance with the given storeName
     */
    public static <K, V, S extends StateStore> Materialized<K, V, S> as(final StoreImplementation storeImplementation)

/**
 * A state store supplier Implementation interface for all types of {@link StateStore}.
 *
 */
public interface StoreImplementation {
    /**
     * Create a {@link KeyValueBytesStoreSupplier}.
     *
     * @param name  name of the store (cannot be {@code null})
     * @return an instance of a {@link KeyValueBytesStoreSupplier} that can be used
     * to build a persistent key-value store
     */
    KeyValueBytesStoreSupplier keyValueSupplier(String name);

    /**
     * Create a {@link WindowBytesStoreSupplier}.
     *
     * @param name                  name of the store (cannot be {@code null})
     * @param retentionPeriod       length of time to retain data in the store (cannot be negative)
     *                              (note that the retention period must be at least long enough to contain the
     *                              windowed data's entire life cycle, from window-start through window-end,
     *                              and for the entire grace period)
     * @param windowSize            size of the windows (cannot be negative)
     * @param retainDuplicates      whether or not to retain duplicates. Turning this on will automatically disable
     *                              caching and means that null values will be ignored.
     * @return an instance of {@link WindowBytesStoreSupplier}
     * @throws IllegalArgumentException if {@code retentionPeriod} or {@code windowSize} can't be represented as {@code long milliseconds}
     * @throws IllegalArgumentException if {@code retentionPeriod} is smaller than {@code windowSize}
    WindowBytesStoreSupplier windowBytesStoreSupplier(String name,
                                                      Duration retentionPeriod,
                                                      Duration windowSize,
                                                      boolean retainDuplicates);


    /**
     * Create a {@link SessionBytesStoreSupplier}.
     * 
     * @param name              name of the store (cannot be {@code null})
     * @param retentionPeriod   length of time to retain data in the store (cannot be negative)
     *                          (note that the retention period must be at least as long enough to
     *                          contain the inactivity gap of the session and the entire grace period.)
     * @return an instance of a {@link  SessionBytesStoreSupplier}
     */
    SessionBytesStoreSupplier sessionBytesStoreSupplier(String name,
                                                        Duration retentionPeriod);
}

KStream stream = ...

// current code to change from RocksDB to in-memory
stream.groupByKey().count(Materialized.as(Stores.inMemoryKeyValueStore("some-name"));

// new code
stream.groupByKey().count(Materialized.as(StoreType.IN_MEMORY));

public class StreamsConfig {
    public static final String DEFAULT_DSL_STORE_TYPE_CONFIG = "default.dsl.store.type";
    private static final String DEFAULT_DSL_STORE_TYPE_DOC = "The default store type used by DSL operators.";

    public static final ROCKS_DB = "rocksDB";
    public static final IN_MEMORY = "in_memory";
    
    .define(DEFAULT_DSL_STORE_TYPE_CONFIG,
            Type.STRING,
            ROCKS_DB,
            in(ROCKS_DB, IN_MEMORY),
            Importance.LOW,
            DEFAULT_DSL_STORE_TYPE_DOC)
}

public class Materialized<K, V, S extends StateStore> {

  public enum StoreType {
    ROCKS_DB,
    IN_MEMORY
  }

  public static <K, V, S extends StateStore> Materialized<K, V, S> as(StoryType storeType);

  public Materialized<K, V, S> withStoreType(StoryType storeType);
}

public class StreamsBuilder {
  @Deprecate
  public synchronized Topology build();
}