CacheBuilder<Object, Object> builder = CacheBuilder.newBuilder();
    assertThrows(IllegalArgumentException.class, () -> builder.initialCapacity(-1));
  }

  public void testInitialCapacity_setTwice() {
    CacheBuilder<Object, Object> builder = CacheBuilder.newBuilder().initialCapacity(16);
    assertThrows(IllegalStateException.class, () -> builder.initialCapacity(16));
  }