code: /*
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * Licensed 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 io.reactivex.rxjava3.observable;
  
  import java.util.HashMap;
  
  import org.junit.Test;
  
  import io.reactivex.rxjava3.core.RxJavaTest;
  import io.reactivex.rxjava3.functions.*;
  import io.reactivex.rxjava3.observable.ObservableEventStream.Event;
  
  public class ObservableScanTests extends RxJavaTest {
  
      @Test
      public void unsubscribeScan() throws Exception {
  
          ObservableEventStream.getEventStream("HTTP-ClusterB", 20)
          .scan(new HashMap<>(), new BiFunction<HashMap<String, String>, Event, HashMap<String, String>>() {
              @Override
              public HashMap<String, String> apply(HashMap<String, String> accum, Event perInstanceEvent) {
                  accum.put("instance", perInstanceEvent.instanceId);
                  return accum;
              }
          })
          .take(10)
          .blockingForEach(new Consumer<HashMap<String, String>>() {
              @Override
              public void accept(HashMap<String, String> pv) {
                  System.out.println(pv);
              }
          });
  
          Thread.sleep(200); // make sure the event streams receive their interrupt
      }
  }
  