class Window {
	//New methods.
	Instant startTime();
	Instant endTime();
}

JoinWindows {
    //Existing methods. Will be deprecated.
    static JoinWindows of(final long timeDifferenceMs) throws IllegalArgumentException;
    JoinWindows before(final long timeDifferenceMs) throws IllegalArgumentException;
    JoinWindows after(final long timeDifferenceMs) throws IllegalArgumentException;	

	//Existing method. Will be removed.
	JoinWindows grace(final long millisAfterWindowEnd);

    //New methods.
    static JoinWindows of(final Duration timeDifference) throws IllegalArgumentException;
    JoinWindows before(final Duration timeDifference) throws IllegalArgumentException;
    JoinWindows after(final Duration timeDifference) throws IllegalArgumentException;
	JoinWindows grace(final Duration afterWindowEnd) throws IllegalArgumentException;
}

Materialized {
	//Existing method. Will be removed.
	Materialized<K, V, S> withRetention(final long retentionMs);

	//New method.
	Materialized<K, V, S> withRetention(final Duration retention) throws IllegalArgumentException;
}

SessionWindows {
	//Existing methods. Will be deprecated.
    static SessionWindows with(final long inactivityGapMs);

	//Existing methods. Will be removed.
	SessionWindows grace(final long millisAfterWindowEnd);

	//New methods.
    static SessionWindows with(final Duration inactivityGap) throws IllegalArgumentException;
	SessionWindows grace(final Duration afterWindowEnd) throws IllegalArgumentException;
}

TimeWindows {
	//Existing methods. Will be deprecated.
	static TimeWindows of(final long sizeMs) throws IllegalArgumentException;
	TimeWindows advanceBy(final long advanceMs);

	//Existing method. Will be removed.
	TimeWindows grace(final long millisAfterWindowEnd);

	//New methods.
	static TimeWindows of(final Duration size) throws IllegalArgumentException;
	TimeWindows advanceBy(final Duration advance);
	TimeWindows grace(final Duration afterWindowEnd);
}

UnlimitedWindows {
	//Existing methods. Will be deprecated.
    UnlimitedWindows startOn(final long startMs) throws IllegalArgumentException;

	//New methods.
    UnlimitedWindows startOn(final Instant start) throws IllegalArgumentException;
}

ProcessorContext {
    //Existing method. Will be deprecated.
    Cancellable schedule(final long intervalMs,
                         final PunctuationType type,
                         final Punctuator callback);

	//New method.
    Cancellable schedule(final Duration interval,
                         final PunctuationType type,
                         final Punctuator callback) throws IllegalArgumentException;
}

ReadOnlyWindowStore<K, V> {
	//New methods.
    WindowStoreIterator<V> fetch(K key, Instant from, Duration duration) throws IllegalArgumentException;
    KeyValueIterator<Windowed<K>, V> fetch(K from, K to, Instant from, Duration duration) throws IllegalArgumentException;
    KeyValueIterator<Windowed<K>, V> fetchAll(Instant from, Duration duration) throws IllegalArgumentException;
}

Stores {
	//Existing methods. Will be deprecated.
	static WindowBytesStoreSupplier persistentWindowStore(final String name,
    	                                                  final long retentionPeriodMs,
        	                                              final long windowSizeMs,
                                                          final boolean retainDuplicates);

	static WindowBytesStoreSupplier persistentWindowStore(final String name,
                                                          final long retentionPeriodMs,
                                                          final long windowSizeMs,
                                                          final boolean retainDuplicates,
                                                          final long segmentIntervalMs);

	//New methods.
	static WindowBytesStoreSupplier persistentWindowStore(final String name,
    	                                                  final Duration retentionPeriod,
        	                                              final Duration windowSize,
                                                          final boolean retainDuplicates) throws IllegalArgumentException;

	static SessionBytesStoreSupplier persistentSessionStore(final String name,
                                                            final Duration retentionPeriod) throws IllegalArgumentException;
}

KafkaStreams {
	//Existing method. Will be deprecated.
	public synchronized boolean close(final long timeout, final TimeUnit timeUnit);

	//New method
	public synchronized boolean close(final Duration timeout) throws IllegalArgumentException;
}