public class TypedEnumMapDemoTest {

    /**
     * Enum-like typed key.
     *
     * We need different enum-key classes for each TypedEnumMap to provide ordinal-based enum
     * uniqueness.
     *
     * @param <T> Key type.
     */
    public static class MyKey<T> extends EnumMapKey<T> {

        public MyKey(Class<T> type) {
            super(type);
        }
    }

    /**
     * Enum-like class.
     */
    public interface MyEnum {

        MyKey<Integer> ENUM_INT_KEY = new MyKey<>(Integer.class);
        MyKey<String> ENUM_STR_KEY = new MyKey<>(String.class);
        MyKey<BigDecimal> ENUM_BD_KEY = new MyKey<BigDecimal>(BigDecimal.class) {
            @Override
            public String name() {
                return "K";
            }
        };
    }

    /**
     * Enum container to construct TypedEnumMap instances.
     */
    public static final EnumMapKeyContainer<MyKey> CONTAINER =
            new DefaultEnumMapKeyContainer<>(MyKey.class, MyEnum.class);

    @Test
    public void testEnumContainer() {
        assertEquals(3, CONTAINER.getElements().size());
        assertEquals(ImmutableSet.of("ENUM_INT_KEY", "ENUM_STR_KEY", "K"),
                CONTAINER.getElements().stream().map(EnumMapKey::name).collect(Collectors.toSet()));
        assertEquals(MyKey.class, CONTAINER.getElementClass());
        assertEquals(CONTAINER.getElements().size() - 1, CONTAINER.getMaxOrdinal());
    }

    @Test
    public void testTypedEnumMap() {
        final TypedEnumMap map = new TypedEnumMap(CONTAINER);
        map.put(MyEnum.ENUM_INT_KEY, 1);
        //map.put(MyEnum.ENUM_INT_KEY, "x");  // compile error
        map.put(MyEnum.ENUM_BD_KEY, BigDecimal.TEN);
        assertEquals(1, map.get(MyEnum.ENUM_INT_KEY).intValue());
        assertEquals(10, map.get(MyEnum.ENUM_BD_KEY).intValue());
        assertNull(map.get(MyEnum.ENUM_STR_KEY));
    }