public void testNulls() throws Exception {
    NullPointerTester tester = new NullPointerTester();
    tester.testAllPublicStaticMethods(ImmutableMultimap.class);
    tester.ignore(ImmutableListMultimap.class.getMethod("get", Object.class));
    tester.testAllPublicInstanceMethods(ImmutableMultimap.of());
    tester.testAllPublicInstanceMethods(ImmutableMultimap.of("a", 1));
  }

  public void testNulls() throws Exception {
    NullPointerTester tester = new NullPointerTester();
    tester.testAllPublicStaticMethods(ImmutableMultimap.class);
    tester.ignore(ImmutableListMultimap.class.getMethod("get", Object.class));
    tester.testAllPublicInstanceMethods(ImmutableMultimap.of());
    tester.testAllPublicInstanceMethods(ImmutableMultimap.of("a", 1));
  }

    }
  }

  @J2ktIncompatible
  @GwtIncompatible // NullPointerTester
  public void testNullPointers() {
    NullPointerTester tester = new NullPointerTester();
    tester.setDefault(double.class, 3.0);
    tester.testAllPublicStaticMethods(DoubleMath.class);
  }

    NullPointerTester tester = new NullPointerTester();
    // Necessary until JDK15:
    // https://bugs.openjdk.org/browse/JDK-8202469
    tester.ignore(Equivalence.class.getMethod("wrap", Object.class));

    tester.testAllPublicStaticMethods(Equivalence.class);
    tester.testAllPublicInstanceMethods(Equivalence.equals());
    tester.testAllPublicInstanceMethods(Equivalence.identity());
  }

import java.util.Spliterator.OfPrimitive;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.Supplier;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tester for {@code Spliterator} implementations.
 *
 * @since 21.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public final class SpliteratorTester<E extends @Nullable Object> {

    ```Python hl_lines="14"
    {!> ../../../docs_src/body_nested_models/tutorial002.py!}
    ```

=== "🐍 3️⃣.9️⃣ & 🔛"

    ```Python hl_lines="14"
    {!> ../../../docs_src/body_nested_models/tutorial002_py39.py!}
    ```

=== "🐍 3️⃣.1️⃣0️⃣ & 🔛"

    ```Python hl_lines="12"
    {!> ../../../docs_src/body_nested_models/tutorial002_py310.py!}
    ```

## ⚒ 🆎

```Python hl_lines="12"
{!../../../docs_src/body_nested_models/tutorial001.py!}
```

これにより、各項目の型は宣言されていませんが、`tags`はある項目のリストになります。

## タイプパラメータを持つリストのフィールド

しかし、Pythonには型や「タイプパラメータ」を使ってリストを宣言する方法があります:

### typingの`List`をインポート

まず、Pythonの標準の`typing`モジュールから`List`をインポートします:

```Python hl_lines="1"
{!../../../docs_src/body_nested_models/tutorial002.py!}
```

### タイプパラメータを持つ`List`の宣言

=== "Python 3.10+"

    ```Python hl_lines="12"
    {!> ../../../docs_src/body_nested_models/tutorial002_py310.py!}
    ```

=== "Python 3.9+"

    ```Python hl_lines="14"
    {!> ../../../docs_src/body_nested_models/tutorial002_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="14"
    {!> ../../../docs_src/body_nested_models/tutorial002.py!}
    ```

## Set 类型

    assertThrows(NullPointerException.class, () -> Atomics.newReferenceArray(null));
  }

  public void testNullPointers() {
    NullPointerTester tester = new NullPointerTester();
    tester.testAllPublicConstructors(Atomics.class); // there aren't any
    tester.testAllPublicStaticMethods(Atomics.class);
  }

    assertThrows(NullPointerException.class, () -> Atomics.newReferenceArray(null));
  }

  public void testNullPointers() {
    NullPointerTester tester = new NullPointerTester();
    tester.testAllPublicConstructors(Atomics.class); // there aren't any
    tester.testAllPublicStaticMethods(Atomics.class);
  }