assertThat(segment.remove(key, hash, newValue)).isFalse();
    assertThat(segment.count).isEqualTo(1);
    assertThat(segment.get(key, hash)).isSameInstanceAs(oldValue);

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

    assertThat(segment.remove(key, hash, newValue)).isFalse();
    assertThat(segment.count).isEqualTo(1);
    assertThat(segment.get(key, hash)).isSameInstanceAs(oldValue);

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

    for (int i = 0; i < iterations; i++) {
      // The entry should get garbage collected and recomputed.
      Object oldValue = ref.get();
      if (oldValue == null) {
        expectedComputations++;
      }
      ref = new WeakReference<>(cache.getUnchecked(1));
      oldValue = null;
      Thread.sleep(i);
      System.gc();
    }

      @ParametricNullness C column,
      V value,
      BinaryOperator<V> mergeFunction) {
    checkNotNull(value);
    V oldValue = table.get(row, column);
    if (oldValue == null) {
      table.put(row, column, value);
    } else {
      V newValue = mergeFunction.apply(oldValue, value);
      if (newValue == null) {
        table.remove(row, column);
      } else {
        table.put(row, column, newValue);

      return key;
    }

    @J2ktIncompatible
    @GwtIncompatible // reload
    @Override
    public ListenableFuture<Integer> reload(Integer key, Integer oldValue) {
      countReload.incrementAndGet();
      return immediateFuture(oldValue + 1);
    }

    public int getLoadCount() {
      return countLoad.get();
    }

    public int getReloadCount() {
      return countReload.get();
    }

      cellRowIndices[i] = requireNonNull(rowIndex.get(rowKey));
      Map<C, V> thisRow = requireNonNull(rows.get(rowKey));
      cellColumnInRowIndices[i] = thisRow.size();
      V oldValue = thisRow.put(columnKey, value);
      checkNoDuplicate(rowKey, columnKey, oldValue, value);
      requireNonNull(columns.get(columnKey)).put(rowKey, value);
    }
    this.cellRowIndices = cellRowIndices;
    this.cellColumnInRowIndices = cellColumnInRowIndices;

  }

  @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);
  }

  }

  public void testPutAndGetInstance() {
    assertThat(map.putInstance(Integer.class, Integer.valueOf(5))).isNull();

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

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

  }

  public void testPutAndGetInstance() {
    assertThat(map.putInstance(Integer.class, new Integer(5))).isNull();

    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));
  }

      cellRowIndices[i] = requireNonNull(rowIndex.get(rowKey));
      Map<C, V> thisRow = requireNonNull(rows.get(rowKey));
      cellColumnInRowIndices[i] = thisRow.size();
      V oldValue = thisRow.put(columnKey, value);
      checkNoDuplicate(rowKey, columnKey, oldValue, value);
      requireNonNull(columns.get(columnKey)).put(rowKey, value);
    }
    this.cellRowIndices = cellRowIndices;
    this.cellColumnInRowIndices = cellColumnInRowIndices;