Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.beam.sdk.util; import static org.hamcrest.Matchers.contains; import static org.hamcrest.Matchers.containsInAnyOrder; import static org.hamcrest.Matchers.equalTo; import static org.hamcrest.Matchers.hasSize; import static org.junit.Assert.assertThat; import org.apache.beam.sdk.transforms.Combine.CombineFn; import org.apache.beam.sdk.transforms.DoFnTester; import org.apache.beam.sdk.transforms.windowing.BoundedWindow; import org.apache.beam.sdk.transforms.windowing.FixedWindows; import org.apache.beam.sdk.transforms.windowing.IntervalWindow; import org.apache.beam.sdk.transforms.windowing.OutputTimeFns; import org.apache.beam.sdk.transforms.windowing.PaneInfo; import org.apache.beam.sdk.transforms.windowing.Sessions; import org.apache.beam.sdk.transforms.windowing.SlidingWindows; import org.apache.beam.sdk.values.KV; import org.apache.beam.sdk.values.TimestampedValue; import org.apache.beam.sdk.values.TupleTag; import com.google.common.collect.ImmutableList; import com.google.common.collect.Iterables; import org.joda.time.Duration; import org.joda.time.Instant; import java.util.Arrays; import java.util.Collection; import java.util.Collections; /** * Properties of {@link GroupAlsoByWindowsDoFn}. * * <p>Some properties may not hold of some implementations, due to restrictions on the context * in which the implementation is applicable. For example, some {@code GroupAlsoByWindows} may not * support merging windows. */ public class GroupAlsoByWindowsProperties { /** * A factory of {@link GroupAlsoByWindowsDoFn} so that the various properties can provide * the appropriate windowing strategy under test. */ public interface GroupAlsoByWindowsDoFnFactory<K, InputT, OutputT> { <W extends BoundedWindow> GroupAlsoByWindowsDoFn<K, InputT, OutputT, W> forStrategy( WindowingStrategy<?, W> strategy); } /** * Tests that for empty input and the given {@link WindowingStrategy}, the provided GABW * implementation produces no output. * * <p>The input type is deliberately left as a wildcard, since it is not relevant. */ public static <K, InputT, OutputT> void emptyInputEmptyOutput( GroupAlsoByWindowsDoFnFactory<K, InputT, OutputT> gabwFactory) throws Exception { WindowingStrategy<?, IntervalWindow> windowingStrategy = WindowingStrategy .of(FixedWindows.of(Duration.millis(10))); DoFnTester<KV<K, Iterable<WindowedValue<InputT>>>, KV<K, OutputT>> result = runGABW(gabwFactory, windowingStrategy, (K) null, // key should never be used Collections.<WindowedValue<InputT>>emptyList()); assertThat(result.peekOutputElements(), hasSize(0)); } /** * Tests that for a simple sequence of elements on the same key, the given GABW implementation * correctly groups them according to fixed windows. */ public static void groupsElementsIntoFixedWindows( GroupAlsoByWindowsDoFnFactory<String, String, Iterable<String>> gabwFactory) throws Exception { WindowingStrategy<?, IntervalWindow> windowingStrategy = WindowingStrategy .of(FixedWindows.of(Duration.millis(10))); DoFnTester<KV<String, Iterable<WindowedValue<String>>>, KV<String, Iterable<String>>> result = runGABW( gabwFactory, windowingStrategy, "key", WindowedValue.of("v1", new Instant(1), Arrays.asList(window(0, 10)), PaneInfo.NO_FIRING), WindowedValue.of("v2", new Instant(2), Arrays.asList(window(0, 10)), PaneInfo.NO_FIRING), WindowedValue.of("v3", new Instant(13), Arrays.asList(window(10, 20)), PaneInfo.NO_FIRING)); assertThat(result.peekOutputElements(), hasSize(2)); TimestampedValue<KV<String, Iterable<String>>> item0 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(window(0, 10))); assertThat(item0.getValue().getValue(), containsInAnyOrder("v1", "v2")); assertThat(item0.getTimestamp(), equalTo(window(0, 10).maxTimestamp())); TimestampedValue<KV<String, Iterable<String>>> item1 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(window(10, 20))); assertThat(item1.getValue().getValue(), contains("v3")); assertThat(item1.getTimestamp(), equalTo(window(10, 20).maxTimestamp())); } /** * Tests that for a simple sequence of elements on the same key, the given GABW implementation * correctly groups them into sliding windows. * * <p>In the input here, each element occurs in multiple windows. */ public static void groupsElementsIntoSlidingWindowsWithMinTimestamp( GroupAlsoByWindowsDoFnFactory<String, String, Iterable<String>> gabwFactory) throws Exception { WindowingStrategy<?, IntervalWindow> windowingStrategy = WindowingStrategy .of(SlidingWindows.of(Duration.millis(20)).every(Duration.millis(10))) .withOutputTimeFn(OutputTimeFns.outputAtEarliestInputTimestamp()); DoFnTester<KV<String, Iterable<WindowedValue<String>>>, KV<String, Iterable<String>>> result = runGABW( gabwFactory, windowingStrategy, "key", WindowedValue.of("v1", new Instant(5), Arrays.asList(window(-10, 10), window(0, 20)), PaneInfo.NO_FIRING), WindowedValue.of("v2", new Instant(15), Arrays.asList(window(0, 20), window(10, 30)), PaneInfo.NO_FIRING)); assertThat(result.peekOutputElements(), hasSize(3)); TimestampedValue<KV<String, Iterable<String>>> item0 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(window(-10, 10))); assertThat(item0.getValue().getValue(), contains("v1")); assertThat(item0.getTimestamp(), equalTo(new Instant(5))); TimestampedValue<KV<String, Iterable<String>>> item1 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(window(0, 20))); assertThat(item1.getValue().getValue(), containsInAnyOrder("v1", "v2")); assertThat(item1.getTimestamp(), equalTo(new Instant(10))); TimestampedValue<KV<String, Iterable<String>>> item2 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(window(10, 30))); assertThat(item2.getValue().getValue(), contains("v2")); assertThat(item2.getTimestamp(), equalTo(new Instant(20))); } /** * Tests that for a simple sequence of elements on the same key, the given GABW implementation * correctly groups and combines them according to sliding windows. * * <p>In the input here, each element occurs in multiple windows. */ public static void combinesElementsInSlidingWindows( GroupAlsoByWindowsDoFnFactory<String, Long, Long> gabwFactory, CombineFn<Long, ?, Long> combineFn) throws Exception { WindowingStrategy<?, IntervalWindow> windowingStrategy = WindowingStrategy .of(SlidingWindows.of(Duration.millis(20)).every(Duration.millis(10))) .withOutputTimeFn(OutputTimeFns.outputAtEarliestInputTimestamp()); DoFnTester<KV<String, Iterable<WindowedValue<Long>>>, KV<String, Long>> result = runGABW(gabwFactory, windowingStrategy, "k", WindowedValue.of(1L, new Instant(5), Arrays.asList(window(-10, 10), window(0, 20)), PaneInfo.NO_FIRING), WindowedValue.of(2L, new Instant(15), Arrays.asList(window(0, 20), window(10, 30)), PaneInfo.NO_FIRING), WindowedValue.of(4L, new Instant(18), Arrays.asList(window(0, 20), window(10, 30)), PaneInfo.NO_FIRING)); assertThat(result.peekOutputElements(), hasSize(3)); TimestampedValue<KV<String, Long>> item0 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(window(-10, 10))); assertThat(item0.getValue().getKey(), equalTo("k")); assertThat(item0.getValue().getValue(), equalTo(combineFn.apply(ImmutableList.of(1L)))); assertThat(item0.getTimestamp(), equalTo(new Instant(5L))); TimestampedValue<KV<String, Long>> item1 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(window(0, 20))); assertThat(item1.getValue().getKey(), equalTo("k")); assertThat(item1.getValue().getValue(), equalTo(combineFn.apply(ImmutableList.of(1L, 2L, 4L)))); assertThat(item1.getTimestamp(), equalTo(new Instant(5L))); TimestampedValue<KV<String, Long>> item2 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(window(10, 30))); assertThat(item2.getValue().getKey(), equalTo("k")); assertThat(item2.getValue().getValue(), equalTo(combineFn.apply(ImmutableList.of(2L, 4L)))); assertThat(item2.getTimestamp(), equalTo(new Instant(15L))); } /** * Tests that the given GABW implementation correctly groups elements that fall into overlapping * windows that are not merged. */ public static void groupsIntoOverlappingNonmergingWindows( GroupAlsoByWindowsDoFnFactory<String, String, Iterable<String>> gabwFactory) throws Exception { WindowingStrategy<?, IntervalWindow> windowingStrategy = WindowingStrategy .of(FixedWindows.of(Duration.millis(10))); DoFnTester<KV<String, Iterable<WindowedValue<String>>>, KV<String, Iterable<String>>> result = runGABW( gabwFactory, windowingStrategy, "key", WindowedValue.of("v1", new Instant(1), Arrays.asList(window(0, 5)), PaneInfo.NO_FIRING), WindowedValue.of("v2", new Instant(4), Arrays.asList(window(1, 5)), PaneInfo.NO_FIRING), WindowedValue.of("v3", new Instant(4), Arrays.asList(window(0, 5)), PaneInfo.NO_FIRING)); assertThat(result.peekOutputElements(), hasSize(2)); TimestampedValue<KV<String, Iterable<String>>> item0 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(window(0, 5))); assertThat(item0.getValue().getValue(), containsInAnyOrder("v1", "v3")); assertThat(item0.getTimestamp(), equalTo(window(1, 5).maxTimestamp())); TimestampedValue<KV<String, Iterable<String>>> item1 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(window(1, 5))); assertThat(item1.getValue().getValue(), contains("v2")); assertThat(item1.getTimestamp(), equalTo(window(0, 5).maxTimestamp())); } /** * Tests that the given GABW implementation correctly groups elements into merged sessions. */ public static void groupsElementsInMergedSessions( GroupAlsoByWindowsDoFnFactory<String, String, Iterable<String>> gabwFactory) throws Exception { WindowingStrategy<?, IntervalWindow> windowingStrategy = WindowingStrategy .of(Sessions.withGapDuration(Duration.millis(10))); DoFnTester<KV<String, Iterable<WindowedValue<String>>>, KV<String, Iterable<String>>> result = runGABW( gabwFactory, windowingStrategy, "key", WindowedValue.of("v1", new Instant(0), Arrays.asList(window(0, 10)), PaneInfo.NO_FIRING), WindowedValue.of("v2", new Instant(5), Arrays.asList(window(5, 15)), PaneInfo.NO_FIRING), WindowedValue.of("v3", new Instant(15), Arrays.asList(window(15, 25)), PaneInfo.NO_FIRING)); assertThat(result.peekOutputElements(), hasSize(2)); TimestampedValue<KV<String, Iterable<String>>> item0 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(window(0, 15))); assertThat(item0.getValue().getValue(), containsInAnyOrder("v1", "v2")); assertThat(item0.getTimestamp(), equalTo(window(0, 15).maxTimestamp())); TimestampedValue<KV<String, Iterable<String>>> item1 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(window(15, 25))); assertThat(item1.getValue().getValue(), contains("v3")); assertThat(item1.getTimestamp(), equalTo(window(15, 25).maxTimestamp())); } /** * Tests that the given {@link GroupAlsoByWindowsDoFn} implementation combines elements per * session window correctly according to the provided {@link CombineFn}. */ public static void combinesElementsPerSession(GroupAlsoByWindowsDoFnFactory<String, Long, Long> gabwFactory, CombineFn<Long, ?, Long> combineFn) throws Exception { WindowingStrategy<?, IntervalWindow> windowingStrategy = WindowingStrategy .of(Sessions.withGapDuration(Duration.millis(10))); DoFnTester<KV<String, Iterable<WindowedValue<Long>>>, KV<String, Long>> result = runGABW(gabwFactory, windowingStrategy, "k", WindowedValue.of(1L, new Instant(0), Arrays.asList(window(0, 10)), PaneInfo.NO_FIRING), WindowedValue.of(2L, new Instant(5), Arrays.asList(window(5, 15)), PaneInfo.NO_FIRING), WindowedValue.of(4L, new Instant(15), Arrays.asList(window(15, 25)), PaneInfo.NO_FIRING)); assertThat(result.peekOutputElements(), hasSize(2)); TimestampedValue<KV<String, Long>> item0 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(window(0, 15))); assertThat(item0.getValue().getKey(), equalTo("k")); assertThat(item0.getValue().getValue(), equalTo(combineFn.apply(ImmutableList.of(1L, 2L)))); assertThat(item0.getTimestamp(), equalTo(window(0, 15).maxTimestamp())); TimestampedValue<KV<String, Long>> item1 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(window(15, 25))); assertThat(item1.getValue().getKey(), equalTo("k")); assertThat(item1.getValue().getValue(), equalTo(combineFn.apply(ImmutableList.of(4L)))); assertThat(item1.getTimestamp(), equalTo(window(15, 25).maxTimestamp())); } /** * Tests that for a simple sequence of elements on the same key, the given GABW implementation * correctly groups them according to fixed windows and also sets the output timestamp * according to the policy {@link OutputTimeFns#outputAtEndOfWindow()}. */ public static void groupsElementsIntoFixedWindowsWithEndOfWindowTimestamp( GroupAlsoByWindowsDoFnFactory<String, String, Iterable<String>> gabwFactory) throws Exception { WindowingStrategy<?, IntervalWindow> windowingStrategy = WindowingStrategy .of(FixedWindows.of(Duration.millis(10))).withOutputTimeFn(OutputTimeFns.outputAtEndOfWindow()); DoFnTester<KV<String, Iterable<WindowedValue<String>>>, KV<String, Iterable<String>>> result = runGABW( gabwFactory, windowingStrategy, "key", WindowedValue.of("v1", new Instant(1), Arrays.asList(window(0, 10)), PaneInfo.NO_FIRING), WindowedValue.of("v2", new Instant(2), Arrays.asList(window(0, 10)), PaneInfo.NO_FIRING), WindowedValue.of("v3", new Instant(13), Arrays.asList(window(10, 20)), PaneInfo.NO_FIRING)); assertThat(result.peekOutputElements(), hasSize(2)); TimestampedValue<KV<String, Iterable<String>>> item0 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(window(0, 10))); assertThat(item0.getValue().getValue(), containsInAnyOrder("v1", "v2")); assertThat(item0.getTimestamp(), equalTo(window(0, 10).maxTimestamp())); TimestampedValue<KV<String, Iterable<String>>> item1 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(window(10, 20))); assertThat(item1.getValue().getValue(), contains("v3")); assertThat(item1.getTimestamp(), equalTo(window(10, 20).maxTimestamp())); } /** * Tests that for a simple sequence of elements on the same key, the given GABW implementation * correctly groups them according to fixed windows and also sets the output timestamp * according to the policy {@link OutputTimeFns#outputAtLatestInputTimestamp()}. */ public static void groupsElementsIntoFixedWindowsWithLatestTimestamp( GroupAlsoByWindowsDoFnFactory<String, String, Iterable<String>> gabwFactory) throws Exception { WindowingStrategy<?, IntervalWindow> windowingStrategy = WindowingStrategy .of(FixedWindows.of(Duration.millis(10))) .withOutputTimeFn(OutputTimeFns.outputAtLatestInputTimestamp()); DoFnTester<KV<String, Iterable<WindowedValue<String>>>, KV<String, Iterable<String>>> result = runGABW( gabwFactory, windowingStrategy, "k", WindowedValue.of("v1", new Instant(1), Arrays.asList(window(0, 10)), PaneInfo.NO_FIRING), WindowedValue.of("v2", new Instant(2), Arrays.asList(window(0, 10)), PaneInfo.NO_FIRING), WindowedValue.of("v3", new Instant(13), Arrays.asList(window(10, 20)), PaneInfo.NO_FIRING)); assertThat(result.peekOutputElements(), hasSize(2)); TimestampedValue<KV<String, Iterable<String>>> item0 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(window(0, 10))); assertThat(item0.getValue().getValue(), containsInAnyOrder("v1", "v2")); assertThat(item0.getTimestamp(), equalTo(new Instant(2))); TimestampedValue<KV<String, Iterable<String>>> item1 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(window(10, 20))); assertThat(item1.getValue().getValue(), contains("v3")); assertThat(item1.getTimestamp(), equalTo(new Instant(13))); } /** * Tests that the given GABW implementation correctly groups elements into merged sessions * with output timestamps at the end of the merged window. */ public static void groupsElementsInMergedSessionsWithEndOfWindowTimestamp( GroupAlsoByWindowsDoFnFactory<String, String, Iterable<String>> gabwFactory) throws Exception { WindowingStrategy<?, IntervalWindow> windowingStrategy = WindowingStrategy .of(Sessions.withGapDuration(Duration.millis(10))) .withOutputTimeFn(OutputTimeFns.outputAtEndOfWindow()); DoFnTester<KV<String, Iterable<WindowedValue<String>>>, KV<String, Iterable<String>>> result = runGABW( gabwFactory, windowingStrategy, "k", WindowedValue.of("v1", new Instant(0), Arrays.asList(window(0, 10)), PaneInfo.NO_FIRING), WindowedValue.of("v2", new Instant(5), Arrays.asList(window(5, 15)), PaneInfo.NO_FIRING), WindowedValue.of("v3", new Instant(15), Arrays.asList(window(15, 25)), PaneInfo.NO_FIRING)); assertThat(result.peekOutputElements(), hasSize(2)); TimestampedValue<KV<String, Iterable<String>>> item0 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(window(0, 15))); assertThat(item0.getValue().getValue(), containsInAnyOrder("v1", "v2")); assertThat(item0.getTimestamp(), equalTo(window(0, 15).maxTimestamp())); TimestampedValue<KV<String, Iterable<String>>> item1 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(window(15, 25))); assertThat(item1.getValue().getValue(), contains("v3")); assertThat(item1.getTimestamp(), equalTo(window(15, 25).maxTimestamp())); } /** * Tests that the given GABW implementation correctly groups elements into merged sessions * with output timestamps at the end of the merged window. */ public static void groupsElementsInMergedSessionsWithLatestTimestamp( GroupAlsoByWindowsDoFnFactory<String, String, Iterable<String>> gabwFactory) throws Exception { WindowingStrategy<?, IntervalWindow> windowingStrategy = WindowingStrategy .of(Sessions.withGapDuration(Duration.millis(10))) .withOutputTimeFn(OutputTimeFns.outputAtLatestInputTimestamp()); BoundedWindow unmergedWindow = window(15, 25); DoFnTester<KV<String, Iterable<WindowedValue<String>>>, KV<String, Iterable<String>>> result = runGABW( gabwFactory, windowingStrategy, "k", WindowedValue.of("v1", new Instant(0), Arrays.asList(window(0, 10)), PaneInfo.NO_FIRING), WindowedValue.of("v2", new Instant(5), Arrays.asList(window(5, 15)), PaneInfo.NO_FIRING), WindowedValue.of("v3", new Instant(15), Arrays.asList(unmergedWindow), PaneInfo.NO_FIRING)); assertThat(result.peekOutputElements(), hasSize(2)); BoundedWindow mergedWindow = window(0, 15); TimestampedValue<KV<String, Iterable<String>>> item0 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(mergedWindow)); assertThat(item0.getValue().getValue(), containsInAnyOrder("v1", "v2")); assertThat(item0.getTimestamp(), equalTo(new Instant(5))); TimestampedValue<KV<String, Iterable<String>>> item1 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(unmergedWindow)); assertThat(item1.getValue().getValue(), contains("v3")); assertThat(item1.getTimestamp(), equalTo(new Instant(15))); } /** * Tests that the given {@link GroupAlsoByWindowsDoFn} implementation combines elements per * session window correctly according to the provided {@link CombineFn}. */ public static void combinesElementsPerSessionWithEndOfWindowTimestamp( GroupAlsoByWindowsDoFnFactory<String, Long, Long> gabwFactory, CombineFn<Long, ?, Long> combineFn) throws Exception { WindowingStrategy<?, IntervalWindow> windowingStrategy = WindowingStrategy .of(Sessions.withGapDuration(Duration.millis(10))) .withOutputTimeFn(OutputTimeFns.outputAtEndOfWindow()); BoundedWindow secondWindow = window(15, 25); DoFnTester<?, KV<String, Long>> result = runGABW(gabwFactory, windowingStrategy, "k", WindowedValue.of(1L, new Instant(0), Arrays.asList(window(0, 10)), PaneInfo.NO_FIRING), WindowedValue.of(2L, new Instant(5), Arrays.asList(window(5, 15)), PaneInfo.NO_FIRING), WindowedValue.of(4L, new Instant(15), Arrays.asList(secondWindow), PaneInfo.NO_FIRING)); assertThat(result.peekOutputElements(), hasSize(2)); BoundedWindow firstResultWindow = window(0, 15); TimestampedValue<KV<String, Long>> item0 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(firstResultWindow)); assertThat(item0.getValue().getValue(), equalTo(combineFn.apply(ImmutableList.of(1L, 2L)))); assertThat(item0.getTimestamp(), equalTo(firstResultWindow.maxTimestamp())); TimestampedValue<KV<String, Long>> item1 = Iterables .getOnlyElement(result.peekOutputElementsInWindow(secondWindow)); assertThat(item1.getValue().getValue(), equalTo(combineFn.apply(ImmutableList.of(4L)))); assertThat(item1.getTimestamp(), equalTo(secondWindow.maxTimestamp())); } @SafeVarargs private static <K, InputT, OutputT, W extends BoundedWindow> DoFnTester<KV<K, Iterable<WindowedValue<InputT>>>, KV<K, OutputT>> runGABW( GroupAlsoByWindowsDoFnFactory<K, InputT, OutputT> gabwFactory, WindowingStrategy<?, W> windowingStrategy, K key, WindowedValue<InputT>... values) throws Exception { return runGABW(gabwFactory, windowingStrategy, key, Arrays.asList(values)); } private static <K, InputT, OutputT, W extends BoundedWindow> DoFnTester<KV<K, Iterable<WindowedValue<InputT>>>, KV<K, OutputT>> runGABW( GroupAlsoByWindowsDoFnFactory<K, InputT, OutputT> gabwFactory, WindowingStrategy<?, W> windowingStrategy, K key, Collection<WindowedValue<InputT>> values) throws Exception { TupleTag<KV<K, OutputT>> outputTag = new TupleTag<>(); DoFnRunnerBase.ListOutputManager outputManager = new DoFnRunnerBase.ListOutputManager(); DoFnTester<KV<K, Iterable<WindowedValue<InputT>>>, KV<K, OutputT>> tester = DoFnTester .of(gabwFactory.forStrategy(windowingStrategy)); tester.startBundle(); tester.processElement(KV.<K, Iterable<WindowedValue<InputT>>>of(key, values)); tester.finishBundle(); // Sanity check for corruption for (KV<K, OutputT> elem : tester.peekOutputElements()) { assertThat(elem.getKey(), equalTo(key)); } return tester; } private static BoundedWindow window(long start, long end) { return new IntervalWindow(new Instant(start), new Instant(end)); } }