}

  @J2ktIncompatible
  @GwtIncompatible // reflection
  public void testSuppliersNullChecks() throws Exception {
    new ClassSanityTester()
        .setDefault(Duration.class, Duration.ofSeconds(1))
        .forAllPublicStaticMethods(Suppliers.class)
        .testNulls();
  }

  @J2ktIncompatible
  @GwtIncompatible // reflection

  }

  @J2ktIncompatible
  @GwtIncompatible // reflection
  public void testSuppliersNullChecks() throws Exception {
    new ClassSanityTester()
        .setDefault(Duration.class, Duration.ofSeconds(1))
        .forAllPublicStaticMethods(Suppliers.class)
        .testNulls();
  }

  @J2ktIncompatible
  @GwtIncompatible // reflection

  public void testTimeToLive_negative_duration() {
    CacheBuilder<Object, Object> builder = CacheBuilder.newBuilder();
    assertThrows(
        IllegalArgumentException.class, () -> builder.expireAfterWrite(Duration.ofSeconds(-1)));
  }

  @SuppressWarnings("ReturnValueIgnored")
  public void testTimeToLive_small() {
    CacheBuilder.newBuilder().expireAfterWrite(1, NANOSECONDS).build(identityLoader());
    // well, it didn't blow up.