verify(mock).invalidateAll();
  }

  public void testSize() {
    when(mock.size()).thenReturn(0L);
    assertEquals(0, forward.size());
  }

  public void testStats() {
    when(mock.stats()).thenReturn(null);
    assertNull(forward.stats());
  }

  public void testAsMap() {
    when(mock.asMap()).thenReturn(null);
    assertNull(forward.asMap());
  }

  public void testCleanUp() {

    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();

    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);