private static void putThread(Waiter waiter, Thread newValue) {
    ATOMIC_HELPER.putThread(waiter, newValue);
  }

  /** Non-volatile write of the waiter to the {@link Waiter#next} field. */
  private static void putNext(Waiter waiter, @Nullable Waiter newValue) {
    ATOMIC_HELPER.putNext(waiter, newValue);
  }

  /**

      }

      while (true) {
        int oldValue = existingCounter.get();
        if (oldValue != 0) {
          try {
            int newValue = Math.addExact(oldValue, occurrences);
            if (existingCounter.compareAndSet(oldValue, newValue)) {
              // newValue can't == 0, so no need to check & remove
              return oldValue;
            }
          } catch (ArithmeticException overflow) {

        Entry<Object, Object> entry = warmed.get(i - WARMUP_MIN);
        Object newValue = new Object();
        assertThat(cache.asMap().put(entry.getKey(), newValue)).isSameInstanceAs(entry.getValue());
        // don't let the new entry get GCed
        warmed.add(entryOf(entry.getKey(), newValue));
        Object newKey = new Object();
        assertThat(cache.asMap().put(newKey, entry.getValue())).isNull();

    assertEquals(0, segment.count);

    // same value
    segment.setTableEntryForTesting(index, entry);
    segment.count++;
    assertEquals(1, segment.count);
    assertSame(oldValue, segment.get(key, hash));
    assertTrue(segment.replace(key, hash, oldValue, newValue));
    assertEquals(1, segment.count);
    assertSame(newValue, segment.get(key, hash));

    assertEquals(0, segment.count);

    // same value
    segment.setTableEntryForTesting(index, entry);
    segment.count++;
    assertEquals(1, segment.count);
    assertSame(oldValue, segment.get(key, hash));
    assertTrue(segment.replace(key, hash, oldValue, newValue));
    assertEquals(1, segment.count);
    assertSame(newValue, segment.get(key, hash));

            return valueRef.get();
          }
        };

    assertThat(cache.getIfPresent(new Object())).isNull();

    Object newValue = new Object();
    valueRef.set(newValue);
    assertThat(cache.getIfPresent(new Object())).isSameInstanceAs(newValue);
  }

  public void testGetAllPresent_empty() {
    Cache<Object, Object> cache =
        new AbstractCache<Object, Object>() {
          @Override

   * iterator tests.
   *
   * @return the new container instance
   * @param newValue the new container instance
   */
  @CanIgnoreReturnValue
  protected C resetContainer(C newValue) {
    container = newValue;
    return container;
  }

  /**
   * @see #expectContents(java.util.Collection)
   * @param elements expected contents of {@link #container}

  }

  @CanIgnoreReturnValue
  @Override
  @SuppressWarnings("nullness") // https://github.com/jspecify/jdk/issues/118
  public boolean replace(K key, V oldValue, V newValue) {
    return delegate().replace(key, oldValue, newValue);
  }

    Integer oldValue = map.putInstance(Integer.class, new Integer(7));
    assertEquals(5, (int) oldValue);

    Integer newValue = map.getInstance(Integer.class);
    assertEquals(7, (int) newValue);

    // Won't compile: map.putInstance(Double.class, new Long(42));
  }

  public void testNull() {

    // different value
    assertThat(segment.replace(key, hash, oldValue, newValue)).isFalse();
    assertThat(segment.count).isEqualTo(1);
    assertThat(segment.get(key, hash)).isSameInstanceAs(newValue);

    // cleared
    entry.setValueReference(oldValueRef);
    assertThat(segment.get(key, hash)).isSameInstanceAs(oldValue);
    oldValueRef.clear();