List<Float> one = Arrays.asList(1.0f);
    assertThat(Floats.toArray(one)).isEqualTo(ARRAY1);

    float[] array = {0.0f, 1.0f, 3.0f};

    List<Float> three = Arrays.asList(0.0f, 1.0f, 3.0f);
    assertThat(Floats.toArray(three)).isEqualTo(array);

    assertThat(Floats.toArray(Floats.asList(array))).isEqualTo(array);
  }

  public void testToArray_threadSafe() {

    assertThat(Ints.toArray(one)).isEqualTo(ARRAY1);

    int[] array = {(int) 0, (int) 1, (int) 0xdeadbeef};

    List<Integer> three = Arrays.asList((int) 0, (int) 1, (int) 0xdeadbeef);
    assertThat(Ints.toArray(three)).isEqualTo(array);

    assertThat(Ints.toArray(Ints.asList(array))).isEqualTo(array);
  }

  public void testToArray_threadSafe() {

    List<Float> one = Arrays.asList(1.0f);
    assertThat(Floats.toArray(one)).isEqualTo(ARRAY1);

    float[] array = {0.0f, 1.0f, 3.0f};

    List<Float> three = Arrays.asList(0.0f, 1.0f, 3.0f);
    assertThat(Floats.toArray(three)).isEqualTo(array);

    assertThat(Floats.toArray(Floats.asList(array))).isEqualTo(array);
  }

  public void testToArray_threadSafe() {

```Python hl_lines="4  9-12  25-27"
from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    price: float
    is_offer: Union[bool, None] = None


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):

```Python hl_lines="4  9-12  25-27"
from typing import Optional

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    price: float
    is_offer: Union[bool, None] = None


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):

        assertFalse(emptyIterator.hasNext(), "Empty iterator should have no next element");

        // Note: Standard Iterator would throw NoSuchElementException, but this implementation returns null
        // This is a design choice for this specific implementation
        assertNull(emptyIterator.next(), "This implementation returns null instead of throwing");

        // Verify remove can be called (even though no-op)

そして、それを属性の型として使用することができます:

{* ../../docs_src/body_nested_models/tutorial004.py hl[20] *}

これは **FastAPI** が以下のようなボディを期待することを意味します:

```JSON
{
    "name": "Foo",
    "description": "The pretender",
    "price": 42.0,
    "tax": 3.2,
    "tags": ["rock", "metal", "bar"],
    "image": {
        "url": "http://example.com/baz.jpg",
        "name": "The Foo live"
    }
}
```

   *
   * {@snippet :
   * static final ImmutableBiMap<String, Integer> WORD_TO_INT =
   *     new ImmutableBiMap.Builder<String, Integer>()
   *         .put("one", 1)
   *         .put("two", 2)
   *         .put("three", 3)
   *         .buildOrThrow();
   * }
   *
   * <p>For <i>small</i> immutable bimaps, the {@code ImmutableBiMap.of()} methods are even more
   * convenient.
   *

        assertNotNull(exception);
        assertTrue(exception instanceof java.io.Serializable);
    }

    public void test_stackTrace() {
        // Test that stack trace is preserved
        int statusCode = 500;
        String message = "Error occurred";

        WebApiException exception = new WebApiException(statusCode, message);

        assertNotNull(exception.getStackTrace());

    Iterator<String> iterator = asList("one", "two", "three", "four", "five").iterator();
    IllegalArgumentException expected =
        assertThrows(IllegalArgumentException.class, () -> getOnlyElement(iterator));
    assertThat(expected)
        .hasMessageThat()
        .isEqualTo("expected one element but was: <one, two, three, four, five>");
  }