HashingInputStream in = new HashingInputStream(hashFunction, buffer);

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

    verify(hasher).putByte((byte) 'y');
    verify(hashFunction).newHasher();
    verifyNoMoreInteractions(hashFunction, hasher);
  }

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