@Theory public void shouldHold(@ForAll FooUnboxer b) {
++iterations;
@SuppressWarnings("unchecked")
Foo value = functionValue(new FooGenerator(), new Object[] { new Box<>(new Foo(2)) });
for (int i = 0; i < 10000; ++i)
assertEquals(value, b.unbox(new Box<>(new Foo(2))));
}