transient Class<K> keyTypeOrObjectUnderJ2cl;
  transient Class<V> valueTypeOrObjectUnderJ2cl;

  /**
   * Returns a new, empty {@code EnumBiMap} using the specified key and value types.
   *
   * @param keyType the key type
   * @param valueType the value type
   */
  public static <K extends Enum<K>, V extends Enum<V>> EnumBiMap<K, V> create(
      Class<K> keyType, Class<V> valueType) {
    return new EnumBiMap<>(keyType, valueType);
  }

  private static void assertFreshInstances(Class<?>... types) {
    for (Class<?> type : types) {
      assertFreshInstance(type, 2);
    }
  }

  private static void assertFreshInstance(TypeToken<?> type) {
    assertFreshInstance(type, 3);
  }

  private static void assertFreshInstance(Class<?> type, int instances) {
    assertFreshInstance(TypeToken.of(type), instances);
  }

Hug a été l'un des premiers frameworks à implémenter la déclaration des types de paramètres d'API en utilisant les type hints Python. C'était une excellente idée qui a inspiré d'autres outils à faire de même.

Il utilisait des types personnalisés dans ses déclarations au lieu des types Python standard, mais c'était tout de même un énorme pas en avant.

### Just Modern Python

It's all based on standard **Python type** declarations (thanks to Pydantic). No new syntax to learn. Just standard modern Python.

If you need a 2 minute refresher of how to use Python types (even if you don't use FastAPI), check the short tutorial: [Python Types](python-types.md){.internal-link target=_blank}.

You write standard Python with types:

```Python
from datetime import date

```JSON
{"item_id":"foo"}
```

## Path parameters with types

You can declare the type of a path parameter in the function, using standard Python type annotations:

```Python hl_lines="7"
{!../../docs_src/path_params/tutorial002.py!}
```

In this case, `item_id` is declared to be an `int`.

/// check

 * type {@code Iterable<Integer>}, the map won't be able to detect and throw type error.
 *
 * <p>Like any other {@code Map<Class, Object>}, this map may contain entries for primitive types,
 * and a primitive type and its corresponding wrapper type may map to different values.
 *
 * @param <B> the common supertype that all entries must share; often this is simply {@link Object}

 * type {@code Iterable<Integer>}, the map won't be able to detect and throw type error.
 *
 * <p>Like any other {@code Map<Class, Object>}, this map may contain entries for primitive types,
 * and a primitive type and its corresponding wrapper type may map to different values.
 *
 * @param <B> the common supertype that all entries must share; often this is simply {@link Object}

import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
import javax.annotation.Nonnull;
import javax.annotation.meta.TypeQualifierDefault;

/**
 * Marks all "top-level" types as non-null in a way that is recognized by Kotlin. Note that this

import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
import javax.annotation.Nonnull;
import javax.annotation.meta.TypeQualifierDefault;

/**
 * Marks all "top-level" types as non-null in a way that is recognized by Kotlin. Note that this

import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
import javax.annotation.Nonnull;
import javax.annotation.meta.TypeQualifierDefault;

/**
 * Marks all "top-level" types as non-null in a way that is recognized by Kotlin. Note that this