/**
   * Performs a {@linkplain java.lang.invoke.VarHandle#compareAndSet compare-and-set} operation on
   * {@link #valueField} of {@code future}.
   */
  static boolean casValue(AbstractFutureState<?> future, @Nullable Object expect, Object update) {
    return ATOMIC_HELPER.casValue(future, expect, update);
  }

  /** Returns the value of the future, using a volatile read. */
  final @Nullable Object value() {
    return valueField;
  }

      if (owner.value() != this) {
        // nothing to do, we must have been cancelled, don't bother inspecting the future.
        return;
      }
      Object valueToSet = getFutureValue(future);
      if (casValue(owner, this, valueToSet)) {
        complete(
            owner,
            /*
             * Interruption doesn't propagate through a DelegatingToFuture chain (see

     * anything that might slow down execution on such a hot path. Given that the methods are only
     * package-private, I feel OK with just not testing them for NPE.
     *
     * Note that testing casValue is particularly dangerous because it uses Unsafe under some
     * versions of Java, and apparently Unsafe can cause SIGSEGV instead of NPE—almost as if it's
     * not safe.
     */
    concat(

    assertThat(iterable.firstMatch(equalTo("cool"))).hasValue("cool");
    assertThat(iterable.firstMatch(equalTo("pants"))).hasValue("pants");
    assertThat(iterable.firstMatch(Predicates.alwaysFalse())).isAbsent();
    assertThat(iterable.firstMatch(Predicates.alwaysTrue())).hasValue("cool");
  }

  private static final class IntegerValueOfFunction implements Function<String, Integer> {

        @SuppressWarnings({"unchecked", "nullness"})
        K castKey = (K) key;
        @SuppressWarnings({"unchecked", "nullness"}) // similar to the above
        V castValue = (V) value;

        alertListenerIfPresent(castKey, castValue, RemovalCause.EXPLICIT);
        remove(key);
        return true;
      }
      return false;
    }
  }

  @Override

  }

  public void testTryFind() {
    Iterable<String> list = newArrayList("cool", "pants");
    assertThat(tryFind(list, equalTo("cool"))).hasValue("cool");
    assertThat(tryFind(list, equalTo("pants"))).hasValue("pants");
    assertThat(tryFind(list, Predicates.alwaysTrue())).hasValue("cool");
    assertThat(tryFind(list, Predicates.alwaysFalse())).isAbsent();
    assertCanIterateAgain(list);
  }