map.putInstance(type, ImmutableList.of(1));
    assertEquals(1, map.size());
    assertEquals(ImmutableList.of(1), map.getInstance(type));
  }

  public void testGetInstance_withTypeVariable() {
    assertThrows(
        IllegalArgumentException.class, () -> map.getInstance(this.<Number>anyIterableType()));
  }

  public void testPutInstance_withTypeVariable() {
    assertThrows(