}
  }

  public void testForSupplier() {
    Supplier<Integer> supplier = new CountingSupplier();
    Function<@Nullable Object, Integer> function = Functions.forSupplier(supplier);

    assertEquals(1, (int) function.apply(null));
    assertEquals(2, (int) function.apply("foo"));

    new EqualsTester()
        .addEqualityGroup(function, Functions.forSupplier(supplier))