@Test
public void test() {

    assertNull(lookup.find(Object.class, "zoo"));
    assertThat((Foo) lookup.find(Object.class, "foo"), is(sameInstance(this.foo)));
    assertThat((Bar) lookup.find(Object.class, "bar"), is(sameInstance(this.bar)));
    // even if the symbol matches, if the type isn't valid the return value will be null
    assertNull(lookup.find(String.class, "foo"));
}