| NullPointerTester comes with built-in support for some well known types like | |
| `Optional` and `ImmutableList` via guava's | |
| [`ArbitraryInstances`](https://static.javadoc.io/com.google.guava/guava-testlib/23.0/com/google/common/testing/ArbitraryInstances.html) | |
| class. Explicitly calling `setDefault` for these types is unnecessary. |