*
 * Each line of the `urltestdata.txt` file specifies a test. Lines look like this:
 *
 * ```
 * http://example\t.\norg http://example.org/foo/bar s:http h:example.org p:/
 * ```
 */
class WebPlatformUrlTestData {
  var input: String? = null
  var base: String? = null
  var scheme = ""
  var username = ""
  var password: String? = null
  var host = ""

```

本例中，**FastAPI** 不使用 `__init__`，我们要直接在代码中使用。

## 创建实例

使用以下代码创建类实例：

```Python hl_lines="16"
{!../../docs_src/dependencies/tutorial011.py!}
```

这样就可以**参数化**依赖项，它包含 `checker.fixed_content` 的属性 - `"bar"`。

## 把实例作为依赖项

然后，不要再在 `Depends(checker)` 中使用 `Depends(FixedContentQueryChecker)`， 而是要使用 `checker`，因为依赖项是类实例 - `checker`，不是类。

处理依赖项时，**FastAPI** 以如下方式调用 `checker`：

```Python
checker(q="somequery")
```

///

#### 기본값이 있는 필드를 갖는 값의 데이터

하지만 모델의 필드가 기본값이 있어도 ID가 `bar`인 항목(items)처럼 데이터가 값을 갖는다면:

```Python hl_lines="3  5"
{
    "name": "Bar",
    "description": "The bartenders",
    "price": 62,
    "tax": 20.2
}
```

응답에 해당 값들이 포함됩니다.

#### 기본값과 동일한 값을 갖는 데이터

     * <tr>
     * <td>{@literal foo}</td>
     * <td>{@literal foo}</td>
     * </tr>
     * <tr>
     * <td>{@literal foo_bar}</td>
     * <td>{@literal foo.bar}</td>
     * </tr>
     * <tr>
     * <td>{@literal foo_bar_baz}</td>
     * <td>{@literal foo.bar.baz}</td>
     * </tr>
     * </table>
     *
     * @param beanDelimiter
     *            JavaBeansのデリミタ
     * @return このインスタンス自身
     */

                                        "description": "FastAPI can convert price `strings` to actual `numbers` automatically",
                                        "value": {"name": "Bar", "price": "35.4"},
                                    },
                                    "invalid": {
                                        "summary": "Invalid data is rejected with an error",

                                        "description": "FastAPI can convert price `strings` to actual `numbers` automatically",
                                        "value": {"name": "Bar", "price": "35.4"},
                                    },
                                    "invalid": {
                                        "summary": "Invalid data is rejected with an error",

    mockWebServer: MockWebServer,
  ) {
    setUp(protocol, mockWebServer)
    val pushPromise =
      PushPromise(
        "GET",
        "/foo/bar",
        headersOf("foo", "bar"),
        MockResponse(body = "bar"),
      )
    server.enqueue(
      MockResponse.Builder()
        .body("ABCDE")
        .addPush(pushPromise)
        .build(),
    )

## Create an instance

We could create an instance of this class with:

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[18] *}

And that way we are able to "parameterize" our dependency, that now has `"bar"` inside of it, as the attribute `checker.fixed_content`.

## Use the instance as a dependency

  public void testControlsArraySize() {
    ImmutableSet.Builder<String> builder = new ImmutableSet.Builder<String>();
    for (int i = 0; i < 10; i++) {
      builder.add("foo");
    }
    builder.add("bar");
    RegularImmutableSet<String> set = (RegularImmutableSet<String>) builder.build();
    assertTrue(set.elements.length <= 2 * set.size());
  }

  @GwtIncompatible("internals")
  public void testReusedBuilder() {

```JSON
{
  "item": "The Foo Wrestlers"
}
```

Aber wenn der Client `http://example.com/items/bar` anfragt (ein nicht-existierendes `item_id` `"bar"`), erhält er einen HTTP-Statuscode 404 (der „Not Found“-Fehler), und eine JSON-Response wie folgt:

```JSON
{
  "detail": "Item not found"
}
```

/// tip | "Tipp"