}

  public void testOf_one() {
    ImmutableClassToInstanceMap<Number> map = ImmutableClassToInstanceMap.of(int.class, 1);
    assertEquals(1, map.size());
  }

  public void testCopyOf_map_valid() {
    Map<Class<? extends Number>, Number> in = new HashMap<>();
    in.put(Number.class, 0);
    in.put(Double.class, Math.PI);
    ClassToInstanceMap<Number> map = ImmutableClassToInstanceMap.copyOf(in);