import com.google.cloud.dataflow.sdk.transforms.MapElements; //导入依赖的package包/类
@org.junit.Test
public void loadArtistCreditsByKey() {
  DirectPipeline p = DirectPipeline.createForTest();
  Long artistCreditIds[] = {634509L, 846332L};
  PCollection<String> text = p.apply(Create.of(artistCreditLinesOfJson)).setCoder(StringUtf8Coder.of());
  PCollection<KV<Long, MusicBrainzDataObject>> artistCredits = MusicBrainzTransforms.loadTableFromText(text, "artist_credit_name", "artist_credit");
  PCollection<Long> artistCreditIdPCollection =
      artistCredits.apply(MapElements.via((KV<Long, MusicBrainzDataObject> kv) -> {
            Long k = kv.getKey();
            return k;
          })
              .withOutputType(new TypeDescriptor<Long>() {
              })
      );
  DataflowAssert.that(artistCreditIdPCollection).containsInAnyOrder(634509L, 846332L);
}
 

import com.google.cloud.dataflow.sdk.transforms.MapElements; //导入依赖的package包/类
@org.junit.Test
public void loadArtistsWithMapping() {

  DirectPipeline p = DirectPipeline.createForTest();

  PCollection<String> artistText = p.apply("artist", Create.of(artistLinesOfJson)).setCoder(StringUtf8Coder.of());
  Map<String, PCollectionView<Map<Long, String>>> maps = new HashMap<>();
  PCollection<String> areaMapText = p.apply("area", Create.of(areaLinesOfJson)).setCoder(StringUtf8Coder.of());
  PCollectionView<Map<Long, String>> areamap = MusicBrainzTransforms.loadMapFromText(areaMapText, "id", "area");
  maps.put("area", areamap);
  PCollection<KV<Long, MusicBrainzDataObject>> loadedArtists = MusicBrainzTransforms.loadTableFromText(artistText, "artist", "id", maps);

  PCollection<String> areas = loadedArtists.apply("areaLabels", MapElements.via((KV<Long, MusicBrainzDataObject> row) -> {
    return (String) row.getValue().getColumnValue("area");
  }).withOutputType(new TypeDescriptor<String>() {
  }));

  DataflowAssert.that(areas).satisfies((areaLabels) -> {
    List<String> theList = new ArrayList<>();
    areaLabels.forEach(theList::add);
    assert (theList.contains("Canada"));
    return null;
  });


}
 

import com.google.cloud.dataflow.sdk.transforms.MapElements; //导入依赖的package包/类
@Override
public PCollection<KV<String, Integer>> apply(PCollection<GameEvent> gameEvents) {
  return gameEvents
      .apply(
          MapElements.via((GameEvent event) -> KV.of(event.getKey(field), event.getScore()))
              .withOutputType(new TypeDescriptor<KV<String, Integer>>() {}))
      .apply(Sum.<String>integersPerKey());
}
 

import com.google.cloud.dataflow.sdk.transforms.MapElements; //导入依赖的package包/类
public static void main(String[] args) {
  CustomPipelineOptions options =
      PipelineOptionsFactory.fromArgs(args).withValidation().as(CustomPipelineOptions.class);
  Pipeline p = Pipeline.create(options);

  p.apply(PubsubIO.Read.named("read from PubSub")
      .topic(String.format("projects/%s/topics/%s", options.getSourceProject(), options.getSourceTopic()))
      .timestampLabel("ts")
      .withCoder(TableRowJsonCoder.of()))

   .apply("window 1s", Window.into(FixedWindows.of(Duration.standardSeconds(1))))

   .apply("parse timestamps",
      MapElements.via(
        (TableRow e) ->
          Instant.from(DateTimeFormatter.ISO_DATE_TIME.parse(e.get("timestamp").toString())).toEpochMilli())
      .withOutputType(TypeDescriptor.of(Long.class)))

   .apply("max timestamp in window", Max.longsGlobally().withoutDefaults())

   .apply("transform",
      MapElements.via(
        (Long t) -> {
          TableRow ride = new TableRow();
          ride.set("timestamp", Instant.ofEpochMilli(t).toString());
          return ride;
        })
      .withOutputType(TypeDescriptor.of(TableRow.class)))

   .apply(PubsubIO.Write.named("write to PubSub")
      .topic(String.format("projects/%s/topics/%s", options.getSinkProject(), options.getSinkTopic()))
      .withCoder(TableRowJsonCoder.of()));
  p.run();
}
 

import com.google.cloud.dataflow.sdk.transforms.MapElements; //导入依赖的package包/类
public static void main(String[] args) {
  CustomPipelineOptions options =
      PipelineOptionsFactory.fromArgs(args).withValidation().as(CustomPipelineOptions.class);
  Pipeline p = Pipeline.create(options);

  p.apply(PubsubIO.Read.named("read from PubSub")
      .topic(String.format("projects/%s/topics/%s", options.getSourceProject(), options.getSourceTopic()))
      .timestampLabel("ts")
      .withCoder(TableRowJsonCoder.of()))

   .apply("extract dollars",
      MapElements.via((TableRow x) -> Double.parseDouble(x.get("meter_increment").toString()))
        .withOutputType(TypeDescriptor.of(Double.class)))

   .apply("fixed window", Window.into(FixedWindows.of(Duration.standardMinutes(1))))
   .apply("trigger",
      Window.<Double>triggering(
        AfterWatermark.pastEndOfWindow()
          .withEarlyFirings(AfterProcessingTime.pastFirstElementInPane().plusDelayOf(Duration.standardSeconds(1)))
          .withLateFirings(AfterPane.elementCountAtLeast(1)))
        .accumulatingFiredPanes()
        .withAllowedLateness(Duration.standardMinutes(5)))

   .apply("sum whole window", Sum.doublesGlobally().withoutDefaults())
   .apply("format rides", ParDo.of(new TransformRides()))

   .apply(PubsubIO.Write.named("WriteToPubsub")
      .topic(String.format("projects/%s/topics/%s", options.getSinkProject(), options.getSinkTopic()))
      .withCoder(TableRowJsonCoder.of()));
  p.run();
}
 

import com.google.cloud.dataflow.sdk.transforms.MapElements; //导入依赖的package包/类
public static void main(String[] args) {
  CustomPipelineOptions options =
      PipelineOptionsFactory.fromArgs(args).withValidation().as(CustomPipelineOptions.class);
  Pipeline p = Pipeline.create(options);

  p.apply(PubsubIO.Read.named("read from PubSub")
      .topic(String.format("projects/%s/topics/%s", options.getSourceProject(), options.getSourceTopic()))
      .timestampLabel("ts")
      .withCoder(TableRowJsonCoder.of()))

   .apply("key rides by rideid",
      MapElements.via((TableRow ride) -> KV.of(ride.get("ride_id").toString(), ride))
        .withOutputType(new TypeDescriptor<KV<String, TableRow>>() {}))

   .apply("session windows on rides with early firings",
      Window.<KV<String, TableRow>>into(
        Sessions.withGapDuration(Duration.standardMinutes(60)))
          .triggering(
            AfterWatermark.pastEndOfWindow()
              .withEarlyFirings(AfterProcessingTime.pastFirstElementInPane().plusDelayOf(Duration.millis(2000))))
          .accumulatingFiredPanes()
          .withAllowedLateness(Duration.ZERO))

   .apply("group ride points on same ride", Combine.perKey(new LatestPointCombine()))

   .apply("discard key",
      MapElements.via((KV<String, TableRow> a) -> a.getValue())
        .withOutputType(TypeDescriptor.of(TableRow.class)))

   .apply(PubsubIO.Write.named("WriteToPubsub")
      .topic(String.format("projects/%s/topics/%s", options.getSinkProject(), options.getSinkTopic()))
      .withCoder(TableRowJsonCoder.of()));
  p.run();
}
 

import com.google.cloud.dataflow.sdk.transforms.MapElements; //导入依赖的package包/类
@org.junit.Test
public void joinArtistCreditsWithRecordings() {

  DirectPipeline p = DirectPipeline.createForTest();

  PCollection<String> artistCreditText = p.apply("artistCredits", Create.of(artistCreditLinesOfJson)).setCoder(StringUtf8Coder.of());
  PCollection<KV<Long, MusicBrainzDataObject>> artistCredits = MusicBrainzTransforms.loadTableFromText(artistCreditText, "artist_credit_name", "artist_credit");

  PCollection<String> recordingText = p.apply("recordings", Create.of(recordingLinesOfJson)).setCoder(StringUtf8Coder.of());
  PCollection<KV<Long, MusicBrainzDataObject>> recordings = MusicBrainzTransforms.loadTableFromText(recordingText, "recording", "artist_credit");

  PCollection<MusicBrainzDataObject> joinedRecordings = MusicBrainzTransforms.innerJoin("artist credits with recordings", artistCredits, recordings);

  PCollection<Long> recordingIds = joinedRecordings.apply(MapElements.via((MusicBrainzDataObject mbo) -> (Long) mbo.getColumnValue("recording_id")).
      withOutputType(new TypeDescriptor<Long>() {
      }));

  Long bieberRecording = 17069165L;
  Long bieberRecording2 = 15508507L;


  DataflowAssert.that(recordingIds).satisfies((longs) -> {
    List<Long> theList = new ArrayList<Long>();
    longs.forEach(theList::add);
    assert (theList.contains(bieberRecording));
    assert (theList.contains(bieberRecording2));
    return null;
  });

  PCollection<Long> numberJoined = joinedRecordings.apply("count joined recrodings", Count.globally());
  PCollection<Long> numberOfArtistCredits = artistCredits.apply("count artist credits", Count.globally());

  DirectPipelineRunner.EvaluationResults results = p.run();

  long joinedRecordingsCount = results.getPCollection(numberJoined).get(0);
  assert (448 == joinedRecordingsCount);
}
 

import com.google.cloud.dataflow.sdk.transforms.MapElements; //导入依赖的package包/类
public static void run() {
  DataflowPipelineOptions options = PipelineOptionsFactory.create()
      .as(DataflowPipelineOptions.class);
  options.setRunner(BlockingDataflowPipelineRunner.class);
  options.setProject("chrome-oven-144308");
  options.setFilesToStage(
      detectClassPathResourcesToStage(
          DataflowPipelineRunner.class.getClassLoader()
      )
  );
  options.setStagingLocation("gs://dataflow-chrome-oven-144308/stagingForScheduledPipeline");

  Pipeline p = Pipeline.create(options);

  System.out.println("get here 0");
  p.apply(TextIO.Read.from("gs://dataflow-samples/shakespeare/*"))
      .apply(ParDo.named("ExtractWords").of(new DoFn<String, String>() {
        @Override
        public void processElement(ProcessContext c) {
          System.out.println("get here 1");
          for (String word : c.element().split("[^a-zA-Z']+")) {
            if (!word.isEmpty()) {
              c.output(word);
            }
          }
        }
      }))
      .apply(Count.<String>perElement())
      .apply("FormatResults", MapElements.via(new SimpleFunction<KV<String, Long>, String>() {
        @Override
        public String apply(KV<String, Long> input) {
          System.out.println("get here 3");
          return input.getKey() + ": " + input.getValue();
        }
      }))

      .apply(TextIO.Write.to("gs://dataflow-chrome-oven-144308/scheduled"));

  p.run();
}
 

import com.google.cloud.dataflow.sdk.transforms.MapElements; //导入依赖的package包/类
@Test
public void testText() throws Exception {
  SparkPipelineOptions options = SparkPipelineOptionsFactory.create();
  options.setRunner(SparkPipelineRunner.class);
  Pipeline p = Pipeline.create(options);
  PCollection<String> inputWords = p.apply(Create.of(WORDS)).setCoder(StringUtf8Coder.of());
  PCollection<String> output = inputWords.apply(new WordCount.CountWords())
      .apply(MapElements.via(new WordCount.FormatAsTextFn()));
  output.apply(TextIO.Write.to(outputDir.getAbsolutePath()).withNumShards(3).withSuffix(".txt"));
  EvaluationResult res = SparkPipelineRunner.create().run(p);
  res.close();

  int count = 0;
  Set<String> expected = Sets.newHashSet("hi: 5", "there: 1", "sue: 2", "bob: 2");
  for (File f : tmpDir.getRoot().listFiles(new FileFilter() {
    @Override public boolean accept(File pathname) {
      return pathname.getName().matches("out-.*\\.txt");
    }
  })) {
    count++;
    for (String line : Files.readLines(f, Charsets.UTF_8)) {
      assertTrue(line + " not found", expected.remove(line));
    }
  }
  assertEquals(3, count);
  assertTrue(expected.isEmpty());
}
 

import com.google.cloud.dataflow.sdk.transforms.MapElements; //导入依赖的package包/类
public static void main(String[] args) throws Exception {

    Exercise6Options options =
        PipelineOptionsFactory.fromArgs(args).withValidation().as(Exercise6Options.class);
    // Enforce that this pipeline is always run in streaming mode.
    options.setStreaming(true);
    // Allow the pipeline to be cancelled automatically.
    options.setRunner(DataflowPipelineRunner.class);
    Pipeline pipeline = Pipeline.create(options);

    TableReference sessionsTable = new TableReference();
    sessionsTable.setDatasetId(options.getOutputDataset());
    sessionsTable.setProjectId(options.getProject());
    sessionsTable.setTableId(options.getOutputTableName());

    PCollection<GameEvent> rawEvents = pipeline.apply(new Exercise3.ReadGameEvents(options));

    // Extract username/score pairs from the event stream
    PCollection<KV<String, Integer>> userEvents =
        rawEvents.apply(
            "ExtractUserScore",
            MapElements.via((GameEvent gInfo) -> KV.of(gInfo.getUser(), gInfo.getScore()))
                .withOutputType(new TypeDescriptor<KV<String, Integer>>() {}));

    // [START EXERCISE 6]:
    // Detect user sessions-- that is, a burst of activity separated by a gap from further
    // activity. Find and record the mean session lengths.
    // This information could help the game designers track the changing user engagement
    // as their set of games changes.
    userEvents
        // Window the user events into sessions with gap options.getSessionGap() minutes. Make sure
        // to use an outputTimeFn that sets the output timestamp to the end of the window. This will
        // allow us to compute means on sessions based on their end times, rather than their start
        // times.
        .apply(
            /* TODO: YOUR CODE GOES HERE */
            new ChangeMe<PCollection<KV<String, Integer>>, KV<String, Integer>>())
        // For this use, we care only about the existence of the session, not any particular
        // information aggregated over it, so the following is an efficient way to do that.
        .apply(Combine.perKey(x -> 0))
        // Get the duration per session.
        .apply("UserSessionActivity", ParDo.of(new UserSessionInfoFn()))
        // Re-window to process groups of session sums according to when the sessions complete.
        // In streaming we don't just ask "what is the mean value" we must ask "what is the mean
        // value for some window of time". To compute periodic means of session durations, we
        // re-window the session durations.
        .apply(
            /* TODO: YOUR CODE GOES HERE */
            new ChangeMe<PCollection<Integer>, Integer>())
        // Find the mean session duration in each window.
        .apply(Mean.<Integer>globally().withoutDefaults())
        // Write this info to a BigQuery table.
        .apply(ParDo.named("FormatSessions").of(new FormatSessionWindowFn()))
        .apply(
            BigQueryIO.Write.to(sessionsTable)
                .withSchema(FormatSessionWindowFn.getSchema())
                .withCreateDisposition(CreateDisposition.CREATE_IF_NEEDED)
                .withWriteDisposition(WriteDisposition.WRITE_APPEND));
    // [END EXERCISE 6]:

    // Run the pipeline and wait for the pipeline to finish; capture cancellation requests from the
    // command line.
    PipelineResult result = pipeline.run();
  }
 

import com.google.cloud.dataflow.sdk.transforms.MapElements; //导入依赖的package包/类
public static void main(String[] args) throws Exception {

    Exercise6Options options =
        PipelineOptionsFactory.fromArgs(args).withValidation().as(Exercise6Options.class);
    // Enforce that this pipeline is always run in streaming mode.
    options.setStreaming(true);
    // Allow the pipeline to be cancelled automatically.
    options.setRunner(DataflowPipelineRunner.class);
    Pipeline pipeline = Pipeline.create(options);

    TableReference sessionsTable = new TableReference();
    sessionsTable.setDatasetId(options.getOutputDataset());
    sessionsTable.setProjectId(options.getProject());
    sessionsTable.setTableId(options.getOutputTableName());

    PCollection<GameEvent> rawEvents = pipeline.apply(new Exercise3.ReadGameEvents(options));

    // Extract username/score pairs from the event stream
    PCollection<KV<String, Integer>> userEvents =
        rawEvents.apply(
            "ExtractUserScore",
            MapElements.via((GameEvent gInfo) -> KV.of(gInfo.getUser(), gInfo.getScore()))
                .withOutputType(new TypeDescriptor<KV<String, Integer>>() {}));

    // Detect user sessions-- that is, a burst of activity separated by a gap from further
    // activity. Find and record the mean session lengths.
    // This information could help the game designers track the changing user engagement
    // as their set of games changes.
    userEvents
        .apply(
            Window.named("WindowIntoSessions")
                .<KV<String, Integer>>into(
                    Sessions.withGapDuration(Duration.standardMinutes(options.getSessionGap())))
                .withOutputTimeFn(OutputTimeFns.outputAtEndOfWindow()))
        // For this use, we care only about the existence of the session, not any particular
        // information aggregated over it, so the following is an efficient way to do that.
        .apply(Combine.perKey(x -> 0))
        // Get the duration per session.
        .apply("UserSessionActivity", ParDo.of(new UserSessionInfoFn()))
        // Re-window to process groups of session sums according to when the sessions complete.
        .apply(
            Window.named("WindowToExtractSessionMean")
                .<Integer>into(
                    FixedWindows.of(
                        Duration.standardMinutes(options.getUserActivityWindowDuration()))))
        // Find the mean session duration in each window.
        .apply(Mean.<Integer>globally().withoutDefaults())
        // Write this info to a BigQuery table.
        .apply(ParDo.named("FormatSessions").of(new FormatSessionWindowFn()))
        .apply(
            BigQueryIO.Write.to(sessionsTable)
                .withSchema(FormatSessionWindowFn.getSchema())
                .withCreateDisposition(CreateDisposition.CREATE_IF_NEEDED)
                .withWriteDisposition(WriteDisposition.WRITE_APPEND));

    // Run the pipeline and wait for the pipeline to finish; capture cancellation requests from the
    // command line.
    PipelineResult result = pipeline.run();
  }
 

import com.google.cloud.dataflow.sdk.transforms.MapElements; //导入依赖的package包/类
public static void main(String[] args) throws Exception {

    Exercise5Options options =
        PipelineOptionsFactory.fromArgs(args).withValidation().as(Exercise5Options.class);
    // Enforce that this pipeline is always run in streaming mode.
    options.setStreaming(true);
    // Allow the pipeline to be cancelled automatically.
    options.setRunner(DataflowPipelineRunner.class);
    Pipeline pipeline = Pipeline.create(options);

    TableReference teamTable = new TableReference();
    teamTable.setDatasetId(options.getOutputDataset());
    teamTable.setProjectId(options.getProject());
    teamTable.setTableId(options.getOutputTableName());

    PCollection<GameEvent> rawEvents = pipeline.apply(new Exercise3.ReadGameEvents(options));

    // Extract username/score pairs from the event stream
    PCollection<KV<String, Integer>> userEvents =
        rawEvents.apply(
            "ExtractUserScore",
            MapElements.via((GameEvent gInfo) -> KV.of(gInfo.getUser(), gInfo.getScore()))
                .withOutputType(new TypeDescriptor<KV<String, Integer>>() {}));

    // Calculate the total score per user over fixed windows, and
    // cumulative updates for late data.
    final PCollectionView<Map<String, Integer>> spammersView =
        userEvents
            .apply(
                Window.named("FixedWindowsUser")
                    .<KV<String, Integer>>into(
                        FixedWindows.of(
                            Duration.standardMinutes(options.getFixedWindowDuration()))))

            // Filter out everyone but those with (SCORE_WEIGHT * avg) clickrate.
            // These might be robots/spammers.
            .apply("CalculateSpammyUsers", new CalculateSpammyUsers())
            // Derive a view from the collection of spammer users. It will be used as a side input
            // in calculating the team score sums, below.
            .apply("CreateSpammersView", View.<String, Integer>asMap());

    // Calculate the total score per team over fixed windows,
    // and emit cumulative updates for late data. Uses the side input derived above-- the set of
    // suspected robots-- to filter out scores from those users from the sum.
    // Write the results to BigQuery.
    rawEvents
        .apply(
            Window.named("WindowIntoFixedWindows")
                .<GameEvent>into(
                    FixedWindows.of(Duration.standardMinutes(options.getFixedWindowDuration()))))
        // Filter out the detected spammer users, using the side input derived above.
        .apply(
            ParDo.named("FilterOutSpammers")
                .withSideInputs(spammersView)
                .of(
                    new DoFn<GameEvent, GameEvent>() {
                      @Override
                      public void processElement(ProcessContext c) {
                        // If the user is not in the spammers Map, output the data element.
                        if (c.sideInput(spammersView).get(c.element().getUser().trim()) == null) {
                          c.output(c.element());
                        }
                      }
                    }))
        // Extract and sum teamname/score pairs from the event data.
        .apply("ExtractTeamScore", new Exercise1.ExtractAndSumScore("team"))
        // Write the result to BigQuery
        .apply(ParDo.named("FormatTeamWindows").of(new FormatTeamWindowFn()))
        .apply(
            BigQueryIO.Write.to(teamTable)
                .withSchema(FormatTeamWindowFn.getSchema())
                .withCreateDisposition(CreateDisposition.CREATE_IF_NEEDED)
                .withWriteDisposition(WriteDisposition.WRITE_APPEND));

    // Run the pipeline and wait for the pipeline to finish; capture cancellation requests from the
    // command line.
    PipelineResult result = pipeline.run();
  }
 

import com.google.cloud.dataflow.sdk.transforms.MapElements; //导入依赖的package包/类
public static void main(String[] args) throws Exception {

    Exercise5Options options =
        PipelineOptionsFactory.fromArgs(args).withValidation().as(Exercise5Options.class);
    // Enforce that this pipeline is always run in streaming mode.
    options.setStreaming(true);
    // Allow the pipeline to be cancelled automatically.
    options.setRunner(DataflowPipelineRunner.class);
    Pipeline pipeline = Pipeline.create(options);

    TableReference teamTable = new TableReference();
    teamTable.setDatasetId(options.getOutputDataset());
    teamTable.setProjectId(options.getProject());
    teamTable.setTableId(options.getOutputTableName());

    PCollection<GameEvent> rawEvents = pipeline.apply(new Exercise3.ReadGameEvents(options));

    // Extract username/score pairs from the event stream
    PCollection<KV<String, Integer>> userEvents =
        rawEvents.apply(
            "ExtractUserScore",
            MapElements.via((GameEvent gInfo) -> KV.of(gInfo.getUser(), gInfo.getScore()))
                .withOutputType(new TypeDescriptor<KV<String, Integer>>() {}));

    // Calculate the total score per user over fixed windows, and
    // cumulative updates for late data.
    final PCollectionView<Map<String, Integer>> spammersView =
        userEvents
            .apply(
                Window.named("FixedWindowsUser")
                    .<KV<String, Integer>>into(
                        FixedWindows.of(
                            Duration.standardMinutes(options.getFixedWindowDuration()))))

            // Filter out everyone but those with (SCORE_WEIGHT * avg) clickrate.
            // These might be robots/spammers.
            .apply("CalculateSpammyUsers", new CalculateSpammyUsers())
            // Derive a view from the collection of spammer users. It will be used as a side input
            // in calculating the team score sums, below.
            .apply("CreateSpammersView", View.<String, Integer>asMap());

    // [START EXERCISE 5 PART b]:
    // Calculate the total score per team over fixed windows,
    // and emit cumulative updates for late data. Uses the side input derived above-- the set of
    // suspected robots-- to filter out scores from those users from the sum.
    // Write the results to BigQuery.
    rawEvents
        .apply(
            Window.named("WindowIntoFixedWindows")
                .<GameEvent>into(
                    FixedWindows.of(Duration.standardMinutes(options.getFixedWindowDuration()))))
        // Filter out the detected spammer users, using the side input derived above.
        //  Use ParDo with spammersView side input to filter out spammers.
        .apply(/* TODO: YOUR CODE GOES HERE */ new ChangeMe<PCollection<GameEvent>, GameEvent>())
        // Extract and sum teamname/score pairs from the event data.
        .apply("ExtractTeamScore", new Exercise1.ExtractAndSumScore("team"))
        // Write the result to BigQuery
        .apply(ParDo.named("FormatTeamWindows").of(new FormatTeamWindowFn()))
        .apply(
            BigQueryIO.Write.to(teamTable)
                .withSchema(FormatTeamWindowFn.getSchema())
                .withCreateDisposition(CreateDisposition.CREATE_IF_NEEDED)
                .withWriteDisposition(WriteDisposition.WRITE_APPEND));
    // [START EXERCISE 5 PART b]:

    // Run the pipeline and wait for the pipeline to finish; capture cancellation requests from the
    // command line.
    PipelineResult result = pipeline.run();
  }