assertEquals(Integer.valueOf(20), map.get(10));
    assertEquals(Integer.valueOf(0), map.get(20));
    assertEquals(Integer.valueOf(1), map.get(30));
    assertEquals(Integer.valueOf(2), map.get(54));
    assertEquals(Integer.valueOf(3), map.get(443));
    assertEquals(Integer.valueOf(4), map.get(1));
    assertEquals(Integer.valueOf(5), cache.get(6));

  }

  private static final BigInteger MAX_LONG = BigInteger.valueOf(Long.MAX_VALUE);
  private static final BigInteger MIN_LONG = BigInteger.valueOf(Long.MIN_VALUE);

  private static long saturatedCast(BigInteger big) {
    if (big.compareTo(MAX_LONG) > 0) {
      return Long.MAX_VALUE;
    }
    if (big.compareTo(MIN_LONG) < 0) {
      return Long.MIN_VALUE;
    }
    return big.longValue();
  }

   */
  @CanIgnoreReturnValue
  public static UnsignedLong valueOf(BigInteger value) {
    checkNotNull(value);
    checkArgument(
        value.signum() >= 0 && value.bitLength() <= Long.SIZE,
        "value (%s) is outside the range for an unsigned long value",
        value);
    return fromLongBits(value.longValue());
  }

  /**

      BigInteger.valueOf(Long.MAX_VALUE)
          .multiply(BigInteger.valueOf(3L))
          .divide(BigInteger.valueOf(4L))
          .doubleValue();
  static final double LARGE_LONG_VALUES_POPULATION_VARIANCE =
      BigInteger.valueOf(Long.MAX_VALUE)
          .multiply(BigInteger.valueOf(Long.MAX_VALUE))
          .divide(BigInteger.valueOf(16L))
          .doubleValue();

  // Stats instances:

    assertEquals(Integer.valueOf(20), map.get(10));
    assertEquals(Integer.valueOf(0), map.get(20));
    assertEquals(Integer.valueOf(1), map.get(30));
    assertEquals(Integer.valueOf(2), map.get(54));
    assertEquals(Integer.valueOf(3), map.get(443));
    assertEquals(Integer.valueOf(4), map.get(1));
    assertEquals(Integer.valueOf(5), cache.get(6));

    new RoundToDoubleTester(BigDecimal.valueOf((-1L << 54) - 4))
        .setExpectation(-Math.pow(2, 54) - 4, values())
        .test();
  }

  public void testRoundToDouble_minDouble() {
    BigDecimal minDoubleAsBD = new BigDecimal(-Double.MAX_VALUE);
    new RoundToDoubleTester(minDoubleAsBD).setExpectation(-Double.MAX_VALUE, values()).test();
  }

    assertEquals(Integer.valueOf(3), cache.getUnchecked(2));
    expectedReloads++;
    assertEquals(expectedLoads, loader.getLoadCount());
    assertEquals(expectedReloads, loader.getReloadCount());

    ticker.advance(1, MILLISECONDS);
    assertEquals(Integer.valueOf(1), cache.getUnchecked(0));
    assertEquals(Integer.valueOf(-1), cache.getUnchecked(1));
    assertEquals(Integer.valueOf(3), cache.getUnchecked(2));

  }

  private static final BigInteger MAX_INT = BigInteger.valueOf(Integer.MAX_VALUE);
  private static final BigInteger MIN_INT = BigInteger.valueOf(Integer.MIN_VALUE);

  private static int saturatedCast(BigInteger big) {
    if (big.compareTo(MAX_INT) > 0) {
      return Integer.MAX_VALUE;
    }
    if (big.compareTo(MIN_INT) < 0) {
      return Integer.MIN_VALUE;
    }
    return big.intValue();
  }

      assertWithMessage(UnsignedLongs.toString(value))
          .that(UnsignedLong.fromLongBits(value).longValue())
          .isEqualTo(value);
    }
  }

  public void testAsUnsignedBigIntegerValue() {
    for (long value : TEST_LONGS) {
      BigInteger expected =
          (value >= 0)
              ? BigInteger.valueOf(value)
              : BigInteger.valueOf(value).add(BigInteger.ZERO.setBit(64));

    }
  }

  public void testPutIfAbsent() {
    TestMap map = new TestMap();
    map.put("foo", 1);
    assertEquals(Integer.valueOf(1), map.putIfAbsent("foo", 2));
    assertEquals(Integer.valueOf(1), map.get("foo"));
    assertNull(map.putIfAbsent("bar", 3));
    assertEquals(Integer.valueOf(3), map.get("bar"));
  }

  public void testRemove() {
    TestMap map = new TestMap();
    map.put("foo", 1);