assertEquals(out.toByteArray().length, ceilToMultiple(expectedBytes, chunkSize));
      assertEquals(expectedBytes / chunkSize, processCalled);
      assertEquals(expectedBytes % chunkSize != 0, remainingCalled);
    }

    // returns the minimum x such as x >= a && (x % b) == 0
    private static int ceilToMultiple(int a, int b) {
      int remainder = a % b;