new EqualsTester()
        .addEqualityGroup(Suppliers.ofInstance("foo"), Suppliers.ofInstance("foo"))
        .addEqualityGroup(Suppliers.ofInstance("bar"))
        .testEquals();
  }

  public void testCompose_equals() {
    new EqualsTester()
        .addEqualityGroup(
            Suppliers.compose(Functions.constant(1), Suppliers.ofInstance("foo")),

    new EqualsTester()
        .addEqualityGroup(Suppliers.ofInstance("foo"), Suppliers.ofInstance("foo"))
        .addEqualityGroup(Suppliers.ofInstance("bar"))
        .testEquals();
  }

  public void testCompose_equals() {
    new EqualsTester()
        .addEqualityGroup(
            Suppliers.compose(Functions.constant(1), Suppliers.ofInstance("foo")),

    }
  }

  @J2ktIncompatible
  @GwtIncompatible // threads
  public void testRenaming() throws Exception {
    String oldName = Thread.currentThread().getName();
    final Supplier<String> newName = Suppliers.ofInstance("MyCrazyThreadName");
    Callable<@Nullable Void> callable =
        new Callable<@Nullable Void>() {
          @Override
          public @Nullable Void call() throws Exception {

    }
  }

  @J2ktIncompatible
  @GwtIncompatible // threads
  public void testRenaming() throws Exception {
    String oldName = Thread.currentThread().getName();
    final Supplier<String> newName = Suppliers.ofInstance("MyCrazyThreadName");
    Callable<@Nullable Void> callable =
        new Callable<@Nullable Void>() {
          @Override
          public @Nullable Void call() throws Exception {

    assertEquals("a", Optional.of("a").or(Suppliers.ofInstance("fallback")));
  }

  public void testOr_supplier_absent() {
    assertEquals("fallback", Optional.absent().or(Suppliers.ofInstance("fallback")));
  }

  public void testOr_nullSupplier_absent() {
    Supplier<Object> nullSupplier = (Supplier<Object>) Suppliers.<@Nullable Object>ofInstance(null);
    Optional<Object> absentOptional = Optional.absent();

  }

  @SuppressWarnings("ReturnValueIgnored")
  public void testMaximumWeight_withoutWeigher() {
    CacheBuilder<Object, Object> builder = CacheBuilder.from(parse("maximumWeight=9000"));
    assertThrows(
        IllegalStateException.class,
        () -> builder.build(CacheLoader.from(Suppliers.ofInstance(null))));
  }

    assertEquals("a", Optional.of("a").or(Suppliers.ofInstance("fallback")));
  }

  public void testOr_supplier_absent() {
    assertEquals("fallback", Optional.absent().or(Suppliers.ofInstance("fallback")));
  }

  public void testOr_nullSupplier_absent() {
    Supplier<Object> nullSupplier = (Supplier<Object>) Suppliers.<@Nullable Object>ofInstance(null);
    Optional<Object> absentOptional = Optional.absent();

  }

  @SuppressWarnings("ReturnValueIgnored")
  public void testMaximumWeight_withoutWeigher() {
    CacheBuilder<Object, Object> builder = CacheBuilder.from(parse("maximumWeight=9000"));
    assertThrows(
        IllegalStateException.class,
        () -> builder.build(CacheLoader.from(Suppliers.ofInstance(null))));
  }

    }

    private static final long serialVersionUID = 0;
  }

  /** Returns a supplier that always supplies {@code instance}. */
  public static <T extends @Nullable Object> Supplier<T> ofInstance(
      @ParametricNullness T instance) {
    return new SupplierOfInstance<>(instance);
  }

  private static class SupplierOfInstance<T extends @Nullable Object>
      implements Supplier<T>, Serializable {

    }

    private static final long serialVersionUID = 0;
  }

  /** Returns a supplier that always supplies {@code instance}. */
  public static <T extends @Nullable Object> Supplier<T> ofInstance(
      @ParametricNullness T instance) {
    return new SupplierOfInstance<>(instance);
  }

  private static class SupplierOfInstance<T extends @Nullable Object>
      implements Supplier<T>, Serializable {