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public interface Suppressed<K> {

/**
 * Marker interface for a buffer configuration that is "strict" in the sense that it will strictly
 * enforce the time bound and never emit early.
 */
interface StrictBufferConfig extends BufferConfig<StrictBufferConfig> {}

interface BufferConfig<BC extends BufferConfig<BC>> {

        /**
         * Create a size-constrained buffer in terms of the maximum number of keys it will store.
         */
        static BufferConfig<?> maxRecords(final long recordLimit);

        /**
         * Set a size constraint on the buffer in terms of the maximum number of keys it will store.
         */
        BC withMaxRecords(final long recordLimit);

        /**
         * Create a size-constrained buffer in terms of the maximum number of bytes it will use.
         */
        static BufferConfig<?> maxBytes(final long byteLimit);

        /**
         * Set a size constraint on the buffer, the maximum number of bytes it will use.
         */
        BC withMaxBytes(final long byteLimit);

        /**
         * Create a buffer unconstrained by size (either keys or bytes).
         *
         * As a result, the buffer will consume as much memory as it needs, dictated by the time bound.
         *
         * If there isn't enough heap available to meet the demand, the application will encounter an
         * {@link OutOfMemoryError} and shut down (not guaranteed to be a graceful exit). Also, note that
         * JVM processes under extreme memory pressure may exhibit poor GC behavior.
         *
         * This is a convenient option if you doubt that your buffer will be that large, but also don't
         * wish to pick particular constraints, such as in testing.
         *
         * This buffer is "strict" in the sense that it will enforce the time bound or crash.
         * It will never emit early.
         */
        static StrictBufferConfig unbounded();

        /**
         * Set the buffer to be unconstrained by size (either keys or bytes).
         *
         * As a result, the buffer will consume as much memory as it needs, dictated by the time bound.
         *
         * If there isn't enough heap available to meet the demand, the application will encounter an
         * {@link OutOfMemoryError} and shut down (not guaranteed to be a graceful exit). Also, note that
         * JVM processes under extreme memory pressure may exhibit poor GC behavior.
         *
         * This is a convenient option if you doubt that your buffer will be that large, but also don't
         * wish to pick particular constraints, such as in testing.
         *
         * This buffer is "strict" in the sense that it will enforce the time bound or crash.
         * It will never emit early.
         */
        StrictBufferConfig withNoBound();

        /**
         * Set the buffer to gracefully shut down the application when any of its constraints are violated
         *
         * This buffer is "strict" in the sense that it will enforce the time bound or shut down.
         * It will never emit early.
         */
        StrictBufferConfig shutDownWhenFull();

        /**
         * Sets the buffer to use on-disk storage if it requires more memory than the constraints allow.
         *
         * This buffer is "strict" in the sense that it will never emit early.
         */
        StrictBufferConfig spillToDiskWhenFull();

        /**
         * Set the buffer to just emit the oldest records when any of its constraints are violated.
         *
         * This buffer is "not strict" in the sense that it may emit early, so it is suitable for reducing
         * duplicate results downstream, but does not promise to eliminate them.
         */
        BufferConfig emitEarlyWhenFull();
}

/**
 * Configure the suppression to emit only the "final results" from the window.
 *
 * By default all Streams operators emit results whenever new results are available.
 * This includes windowed operations.
 *
 * This configuration will instead emit just one result per key for each window, guaranteeing
 * to deliver only the final result. This option is suitable for use cases in which the business logic
 * requires a hard guarantee that only the final result is propagated. For example, sending alerts.
 *
 * To accomplish this, the operator will buffer events from the window until the window close (that is,
 * until the end-time passes, and additionally until the grace period expires). Since windowed operators
 * are required to reject late events for a window whose grace period is expired, there is an additional
 * guarantee that the final results emitted from this suppression are eventually consistent with the upstream
 * operator and its queriable state, if enabled.
 *
 * @param bufferConfig A configuration specifying how much space to use for buffering intermediate results.
 * This is required to be a "strict" config, since it would violate the "final results"
 * property to emit early and then issue an update later.
 * @param <K> The key type for the KTable to apply this suppression to. "Final results" mode is only available
 * on Windowed KTables (this is enforced by the type parameter).
 * @return a "final results" mode suppression configuration
 */
static <K extends Windowed> Suppressed<K> untilWindowCloses(final StrictBufferConfig bufferConfig);

/**
 * Configure the suppression to wait {@code timeToWaitForMoreEvents} amount of time after receiving a record
 * before emitting it further downstream. If another record for the same key arrives in the mean time, it replaces
 * the first record in the buffer but does <em>not</em> re-start the timer.
 *
 * @param timeToWaitForMoreEvents The amount of time to wait, per record, for new events.
 * @param <K> The key type for the KTable to apply this suppression to.
 * @return a suppression configuration
 */
static <K> Suppressed<K> untilTimeLimit(final Duration timeToWaitForMoreEvents);

/**
 * Configure the suppression to wait {@code timeToWaitForMoreEvents} amount of time after receiving a record
 * before emitting it further downstream. If another record for the same key arrives in the mean time, it replaces
 * the first record in the buffer but does <em>not</em> re-start the timer.
 *
 * @param timeToWaitForMoreEvents The amount of time to wait, per record, for new eventsbufferConfig A configuration specifying how much space to use for buffering intermediate results.
 * @param <K> The key type for the KTable to apply this suppression to.
 * @return a suppression configuration
 */
 static <K> Suppressed<K> untilTimeLimit(final Duration timeToWaitForMoreEvents, final BufferConfig bufferConfig);
}