// next map.get()
    when(backingMap.get(KEY)).thenReturn(existingZero);
    // since get returned zero, try a replace; that fails due to a simulated race
    when(backingMap.replace(eq(KEY), eq(existingZero), isA(AtomicInteger.class))).thenReturn(false);
    when(backingMap.putIfAbsent(eq(KEY), isA(AtomicInteger.class))).thenReturn(existing);

    // another map.get()

    // next map.get()
    when(backingMap.get(KEY)).thenReturn(existingZero);
    // since get returned zero, try a replace; that fails due to a simulated race
    when(backingMap.replace(eq(KEY), eq(existingZero), isA(AtomicInteger.class))).thenReturn(false);
    when(backingMap.putIfAbsent(eq(KEY), isA(AtomicInteger.class))).thenReturn(existing);

    // another map.get()

    ExecutorService service = mock(ExecutorService.class);
    when(service.awaitTermination(HALF_SECOND_NANOS, NANOSECONDS))
        .thenReturn(false)
        .thenReturn(true);
    when(service.isTerminated()).thenReturn(true);
    assertTrue(shutdownAndAwaitTermination(service, 1L, SECONDS));
    verify(service).shutdown();

  @Override
  protected void setUp() throws Exception {
    super.setUp();
    hasher = mock(Hasher.class);
    hashFunction = mock(HashFunction.class);

    when(hashFunction.newHasher()).thenReturn(hasher);
  }

  public void testWrite_putSingleByte() throws Exception {
    int b = 'q';
    HashingOutputStream out = new HashingOutputStream(hashFunction, buffer);
    out.write(b);

  @Override
  protected void setUp() throws Exception {
    super.setUp();
    hasher = mock(Hasher.class);
    hashFunction = mock(HashFunction.class);

    when(hashFunction.newHasher()).thenReturn(hasher);
  }

  public void testWrite_putSingleByte() throws Exception {
    int b = 'q';
    HashingOutputStream out = new HashingOutputStream(hashFunction, buffer);
    out.write(b);

    super.setUp();
    hasher = mock(Hasher.class);
    hashFunction = mock(HashFunction.class);
    buffer = new ByteArrayInputStream(testBytes);

    when(hashFunction.newHasher()).thenReturn(hasher);
  }

  public void testRead_putSingleByte() throws Exception {
    HashingInputStream in = new HashingInputStream(hashFunction, buffer);

    int b = in.read();
    assertEquals('y', b);