UnsignedLong unsignedSum = aUnsigned.plus(bUnsigned);
        assertThat(unsignedSum.longValue()).isEqualTo(expected);
      }
    }
  }

  public void testMinus() {
    for (long a : TEST_LONGS) {
      for (long b : TEST_LONGS) {
        UnsignedLong aUnsigned = UnsignedLong.fromLongBits(a);
        UnsignedLong bUnsigned = UnsignedLong.fromLongBits(b);
        long expected =

        UnsignedLong unsignedSum = aUnsigned.plus(bUnsigned);
        assertThat(unsignedSum.longValue()).isEqualTo(expected);
      }
    }
  }

  public void testMinus() {
    for (long a : TEST_LONGS) {
      for (long b : TEST_LONGS) {
        UnsignedLong aUnsigned = UnsignedLong.fromLongBits(a);
        UnsignedLong bUnsigned = UnsignedLong.fromLongBits(b);
        long expected =

  }

  public void testNull() throws Exception {
    for (Striped<?> striped : allImplementations()) {
      new NullPointerTester().testAllPublicInstanceMethods(striped);
    }
  }

  public void testSizes() {
    // not bothering testing all variations, since we know they share implementations
    assertThat(Striped.lock(100).size()).isAtLeast(100);
    assertTrue(Striped.lock(256).size() == 256);

  }

  public void testNull() throws Exception {
    for (Striped<?> striped : allImplementations()) {
      new NullPointerTester().testAllPublicInstanceMethods(striped);
    }
  }

  public void testSizes() {
    // not bothering testing all variations, since we know they share implementations
    assertThat(Striped.lock(100).size()).isAtLeast(100);
    assertTrue(Striped.lock(256).size() == 256);