thrownUnsafeFailure = unsafeFailure;
      // catch absolutely everything and fall through to our 'SafeAtomicHelper'
      // The access control checks that ARFU does means the caller class has to be AbstractFuture
      // instead of SafeAtomicHelper, so we annoyingly define these here
      try {
        helper =
            new SafeAtomicHelper(

    bimap.put(Currency.DOLLAR, "dollar");
    assertEquals("dollar", bimap.get(Currency.DOLLAR));
    assertEquals(Currency.DOLLAR, bimap.inverse().get("dollar"));
  }

  public void testCreateFromMap() {
    /* Test with non-empty Map. */
    Map<Currency, String> map =
        ImmutableMap.of(
            Currency.DOLLAR, "dollar",
            Currency.PESO, "peso",

    bimap.put(Currency.DOLLAR, Country.CANADA);
    assertEquals(Country.CANADA, bimap.get(Currency.DOLLAR));
    assertEquals(Currency.DOLLAR, bimap.inverse().get(Country.CANADA));
  }

  public void testCreateFromMap() {
    /* Test with non-empty Map. */
    Map<Currency, Country> map =
        ImmutableMap.of(
            Currency.DOLLAR, Country.CANADA,
            Currency.PESO, Country.CHILE,

    bimap.put(Currency.DOLLAR, Country.CANADA);
    assertEquals(Country.CANADA, bimap.get(Currency.DOLLAR));
    assertEquals(Currency.DOLLAR, bimap.inverse().get(Country.CANADA));
  }

  public void testCreateFromMap() {
    /* Test with non-empty Map. */
    Map<Currency, Country> map =
        ImmutableMap.of(
            Currency.DOLLAR, Country.CANADA,
            Currency.PESO, Country.CHILE,

    otherwise. Do not persist these and assume they can be read by a future
    version of the library.

5.  Our classes are not designed to protect against a malicious caller. You
    should not use them for communication between trusted and untrusted code.

6.  For the mainline flavor, we test the libraries using OpenJDK 8, 11, and 17

   * {@code invokeAny}. In the latter case, tasks will run serially on the calling thread. Tasks are
   * run to completion before a {@code Future} is returned to the caller (unless the executor has
   * been shutdown).
   *
   * <p>Although all tasks are immediately executed in the thread that submitted the task, this

    }
  }

  @GwtIncompatible // isPrime is GWT-incompatible
  public void testIsPrimeManyConstants() {
    // Test the thorough test inputs, which also includes special constants in the Miller-Rabin
    // tests.
    for (long l : POSITIVE_LONG_CANDIDATES) {
      assertEquals(BigInteger.valueOf(l).isProbablePrime(100), LongMath.isPrime(l));
    }
  }

  //    visible to done(). This is because there is no happens before edge between the write and a
  //    (hypothetical) unsafe read by our caller. Note: adding 'volatile' does not fix this issue,
  //    it would just add an edge such that if done() observed non-null, then it would also

    bimap.put(Currency.DOLLAR, "dollar");
    assertEquals("dollar", bimap.get(Currency.DOLLAR));
    assertEquals(Currency.DOLLAR, bimap.inverse().get("dollar"));
  }

  public void testCreateFromMap() {
    /* Test with non-empty Map. */
    Map<Currency, String> map =
        ImmutableMap.of(
            Currency.DOLLAR, "dollar",
            Currency.PESO, "peso",

    return (nullableReference == null) ? Optional.<T>absent() : new Present<T>(nullableReference);
  }

  Optional() {}

  /**
   * Returns {@code true} if this holder contains a (non-null) instance.
   *
   * <p><b>Comparison to {@code java.util.Optional}:</b> no differences.
   */
  public abstract boolean isPresent();

  /**