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.internal.observers;
  
  import io.reactivex.rxjava3.disposables.Disposable;
  import org.junit.Test;
  
  import io.reactivex.rxjava3.annotations.Nullable;
  import io.reactivex.rxjava3.core.RxJavaTest;
  import io.reactivex.rxjava3.observers.TestObserver;
  import io.reactivex.rxjava3.testsupport.TestObserverEx;
  
  public class BasicFuseableObserverTest extends RxJavaTest {
  
      @Test(expected = UnsupportedOperationException.class)
      public void offer() {
          TestObserverEx<Integer> to = new TestObserverEx<>();
          BasicFuseableObserver<Integer, Integer> o = new BasicFuseableObserver<Integer, Integer>(to) {
              @Nullable
              @Override
              public Integer poll() throws Exception {
                  return null;
              }
  
              @Override
              public int requestFusion(int mode) {
                  return 0;
              }
  
              @Override
              public void onNext(Integer value) {
              }
  
              @Override
              protected boolean beforeDownstream() {
                  return false;
              }
          };
  
          o.onSubscribe(Disposable.disposed());
  
          to.assertNotSubscribed();
  
          o.offer(1);
      }
  
      @Test(expected = UnsupportedOperationException.class)
      public void offer2() {
          BasicFuseableObserver<Integer, Integer> o = new BasicFuseableObserver<Integer, Integer>(new TestObserver<>()) {
              @Nullable
              @Override
              public Integer poll() throws Exception {
                  return null;
              }
  
              @Override
              public int requestFusion(int mode) {
                  return 0;
              }
  
              @Override
              public void onNext(Integer value) {
              }
          };
  
          o.offer(1, 2);
      }
  }
  