*     fieldDesc.getFieldValue(foo); // Retrieve the value of Foo's field
 * }
 *
 * for (ConstructorDesc constructorDesc : beanDesc.getConstructorDescs()) {
 *     constructorDesc.newInstance(...); // Create an instance of Foo
 * }
 *
 * for (String methodName : beanDesc.getMethodNames()) {
 *     for (MethodDesc methodDesc : beanDesc.getMethodDescs(methodName)) {
 *         methodDesc.invoke(foo, ...); // Invoke Foo's method
 *     }

Значение параметра пути `item_id` будет передано в функцию в качестве аргумента `item_id`.

Если запустите этот пример и перейдёте по адресу: <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a>, то увидите ответ:

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

## Параметры пути с типами

Вы можете объявить тип параметра пути в функции, используя стандартные аннотации типов Python.

Wenn Sie mit einer *Pfadoperation* kommunizieren, die zwei HTTP-Header sendet, wie:

```
X-Token: foo
X-Token: bar
```

Dann wäre die Response:

```JSON
{
    "X-Token values": [
        "bar",
        "foo"
    ]
}
```

## Zusammenfassung

Deklarieren Sie Header mittels `Header`, auf die gleiche Weise wie bei `Query`, `Path` und `Cookie`.

 *
 * <p>For example, an XML escaper would convert the literal string {@code "Foo<Bar>"} into {@code
 * "Foo&lt;Bar&gt;"} to prevent {@code "<Bar>"} from being confused with an XML tag. When the
 * resulting XML document is parsed, the parser API will return this text as the original literal
 * string {@code "Foo<Bar>"}.
 *
 * <p>A {@code CharEscaper} instance is required to be stateless, and safe when used concurrently by

                </div>
            </div>
        </section>
    </div>
    <jsp:include page="/WEB-INF/view/common/admin/footer.jsp"></jsp:include>
</div>
<jsp:include page="/WEB-INF/view/common/admin/foot.jsp"></jsp:include>
</body>

  public void testCustomEscaper_withpercent() {
    UnicodeEscaper e = new PercentEscaper("%", false);
    assertEquals("foo%7Cbar", e.escape("foo|bar"));
    assertEquals("foo%7Cbar", e.escape("foo%7Cbar")); // idempotent
  }

  /** Test that giving a null 'safeChars' string causes a {@link NullPointerException}. */
  public void testBadArguments_null() {

Esto significaría que **FastAPI** esperaría un cuerpo similar a:

```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"
    }
}
```

Nuevamente, haciendo solo esa declaración, con **FastAPI** obtienes:

    Iterable<String> iterable = singletonList("foo");
    assertEquals("foo", getOnlyElement(iterable));
  }

  public void testGetOnlyElement_noDefault_empty() {
    Iterable<String> iterable = emptyList();
    assertThrows(NoSuchElementException.class, () -> getOnlyElement(iterable));
  }

  public void testGetOnlyElement_noDefault_multiple() {
    Iterable<String> iterable = asList("foo", "bar");

                </div>
            </la:form>
        </section>
    </div>
    <jsp:include page="/WEB-INF/view/common/admin/footer.jsp"></jsp:include>
</div>
<jsp:include page="/WEB-INF/view/common/admin/foot.jsp"></jsp:include>
</body>

     *       {@code {"--module-path", "dir\path1;dir\path2"}} on Windows.</li>
     *   <li>If this type was created by {@code JavaPathType.patchModule("foo.bar")}, then the method returns
     *       {@code {"--patch-module", "foo.bar=dir/path1:dir/path2"}} on Unix or
     *       {@code {"--patch-module", "foo.bar=dir\path1;dir\path2"}} on Windows.</li>
     * </ul>
     *
     * @param paths the path to format as a string