assertNull(map.put(one, two));
    assertSame(two, map.get(one));
    map.putAll(ImmutableMap.of(two, three));
    assertSame(three, map.get(two));
    assertSame(two, map.putIfAbsent(one, three));
    assertSame(two, map.get(one));
    assertNull(map.putIfAbsent(three, one));
    assertSame(one, map.get(three));
    assertSame(two, map.replace(one, three));
    assertSame(three, map.get(one));

        Entry<Object, Object> entry = warmed.get(i - WARMUP_MIN);
        Object newValue = new Object();
        assertSame(entry.getValue(), cache.asMap().putIfAbsent(entry.getKey(), newValue));
        Object newKey = new Object();
        assertNull(cache.asMap().putIfAbsent(newKey, entry.getValue()));
        // this getUnchecked() call shouldn't be a cache miss; verified below

   * zero, associate it with {@code newValue}. Returns the previous value associated with {@code
   * key}, or zero if there was no mapping for {@code key}.
   */
  long putIfAbsent(K key, long newValue) {
    AtomicBoolean noValue = new AtomicBoolean(false);
    Long result =
        map.compute(
            key,
            (k, oldValue) -> {

    assertEquals(Integer.valueOf(50), asMap.get(10));
    assertEquals(null, cache.getIfPresent(2));
    assertEquals(null, asMap.get(2));

    asMap.putIfAbsent(2, 20);
    asMap.putIfAbsent(10, 20);

    assertEquals(Integer.valueOf(20), cache.getIfPresent(2));
    assertEquals(Integer.valueOf(20), asMap.get(2));
    assertEquals(Integer.valueOf(50), cache.getIfPresent(10));

        Entry<Object, Object> entry = warmed.get(i - WARMUP_MIN);
        Object newValue = new Object();
        assertSame(entry.getValue(), cache.asMap().putIfAbsent(entry.getKey(), newValue));
        Object newKey = new Object();
        assertNull(cache.asMap().putIfAbsent(newKey, entry.getValue()));
        // this getUnchecked() call shouldn't be a cache miss; verified below

      if (eventSubscribers == null) {
        CopyOnWriteArraySet<Subscriber> newSet = new CopyOnWriteArraySet<>();
        eventSubscribers =
            MoreObjects.firstNonNull(subscribers.putIfAbsent(eventType, newSet), newSet);
      }

      eventSubscribers.addAll(eventMethodsInListener);
    }
  }

  /** Unregisters all subscribers on the given listener object. */
  void unregister(Object listener) {

        destroyProcess(sessionId);
        JobProcess jobProcess;
        try {
            jobProcess = new JobProcess(pb.start(), bufferSize, outputCallback);
            destroyProcess(sessionId, runningProcessMap.putIfAbsent(sessionId, jobProcess));
            return jobProcess;
        } catch (final IOException e) {
            throw new JobProcessingException("Crawler Process terminated.", e);
        }
    }

    /**

        QueueHolder queueHolder = sessionCache.get(sessionId);
        if (queueHolder == null) {
            queueHolder = new QueueHolder();
            final QueueHolder prevQueueHolder = sessionCache.putIfAbsent(sessionId, queueHolder);
            return prevQueueHolder == null ? queueHolder : prevQueueHolder;
        }
        return queueHolder;
    }

    /**

                        byte[] nonce = context.generateNonce();
                        String nonceStr = Arrays.toString(nonce);
                        if (allNonces.putIfAbsent(nonceStr, true) != null) {
                            collisions.incrementAndGet();
                        }
                    }
                } finally {
                    latch.countDown();

        alertListenerIfPresent(entry.getKey(), entry.getValue().getValue(), RemovalCause.EXPLICIT);
      }
    }
    cachingHashMap.clear();
  }

  @Override
  public V putIfAbsent(K key, V value) {
    V currentValue = get(key);
    if (currentValue != null) {
      return currentValue;
    }
    return put(key, value);
  }

  @CanIgnoreReturnValue
  @Override