@SuppressWarnings("unused") // Required for automatic type inference
  public static <K> Builder0<K> forClass(final Class<K> type) {
    return new Builder0<>();
  }
@SuppressFBWarnings("RV_RETURN_VALUE_IGNORED_NO_SIDE_EFFECT")
  @Test
  public void shouldWorkWithSuppliersR2() {
    // Given:
    handlerMapR2 = HandlerMaps.forClass(BaseType.class)
        .withArgTypes(String.class, Integer.class)
        .withReturnType(Number.class)
        .put(LeafTypeA.class, () -> handlerR2_1)
        .build();

    // When:
    handlerMapR2.get(LeafTypeA.class).handle("A", 2, LEAF_A);

    // Then:
    verify(handlerR2_1).handle("A", 2, LEAF_A);
  }