* non-nullable {@code cause}, as many users expect to find one.
   */
  public ExecutionError(@CheckForNull String message, @CheckForNull Error cause) {
    super(message, cause);
  }

  /**
   * Creates a new instance with {@code null} as its detail message and the given cause. Prefer to
   * provide a non-nullable {@code cause}, as many users expect to find one.
   */

│   │   ├── items.py     # 「items」子模块，例如 import app.routers.items
│   │   └── users.py     # 「users」子模块，例如 import app.routers.users
│   └── internal         # 「internal」是一个「Python 子包」
│       ├── __init__.py  # 使「internal」成为一个「Python 子包」
│       └── admin.py     # 「admin」子模块，例如 import app.internal.admin
```

## `APIRouter`

假设专门用于处理用户逻辑的文件是位于 `/app/routers/users.py` 的子模块。

你希望将与用户相关的*路径操作*与其他代码分开，以使其井井有条。

🕐❔ 🏗 *➡ 🛠️*, 👆 💪 🔎 ⚠ 🌐❔ 👆 ✔️ 🔧 ➡.

💖 `/users/me`, ➡️ 💬 👈 ⚫️ 🤚 📊 🔃 ⏮️ 👩‍💻.

& ⤴️ 👆 💪 ✔️ ➡ `/users/{user_id}` 🤚 💽 🔃 🎯 👩‍💻 👩‍💻 🆔.

↩️ *➡ 🛠️* 🔬 ✔, 👆 💪 ⚒ 💭 👈 ➡ `/users/me` 📣 ⏭ 1️⃣ `/users/{user_id}`:

```Python hl_lines="6  11"
{!../../docs_src/path_params/tutorial003.py!}
```

⏪, ➡ `/users/{user_id}` 🔜 🏏 `/users/me`, "💭" 👈 ⚫️ 📨 🔢 `user_id` ⏮️ 💲 `"me"`.

     * @return This request, never {@code null}.
     */
    SettingsBuildingRequest setUserSettingsFile(File userSettingsFile);

    /**
     * Gets the user settings source.
     *
     * @return The user settings source or {@code null} if none.
     */
    SettingsSource getUserSettingsSource();

    /**

    response = client.get("/user")
    assert response.json() == {
        "user": "john",
        "scopes": ["foo", "bar"],
        "data": [3, 4, 5],
    }
    app.dependency_overrides = {}


def test_override_security():
    app.dependency_overrides[get_user] = get_user_override
    response = client.get("/user")
    assert response.json() == {
        "user": "alice",
        "scopes": ["foo", "bar"],

import org.apache.maven.api.annotations.Nullable;

/**
 * Service used to interact with the end user.
 *
 * @since 4.0.0
 */
@Experimental
public interface Prompter extends Service {
    /**
     * Prompts the user for a string.
     *
     * @param message the message to display to the user
     * @return the string entered by the user
     * @throws PrompterException if an exception occurs
     */
    @Nonnull

 *       collection. Undefined behavior and bugs will result. It's generally best to avoid using
 *       mutable objects as elements at all, as many users may expect your "immutable" object to be
 *       <i>deeply</i> immutable.
 * </ul>
 *
 * <h4>Performance notes</h4>
 *
 * <ul>

        Files.createDirectories(mavenConf);
        Path mavenUserProps = mavenConf.resolve("maven.properties");
        Files.writeString(mavenUserProps, "${includes} = ?\"/user/ma ven.properties\",  ?/foo/bar\n");
        Path userDirectory = fs.getPath("/user");
        Files.createDirectories(userDirectory);
        Path propsPath = userDirectory.resolve("ma ven.properties");

    /**
     * The goal name for the Mojo, that users will reference from the command line to execute the Mojo directly, or
     * inside a POM in order to provide Mojo-specific configuration.
     */
    private String goal;

    /**
     * Defines a default phase to bind a mojo execution to if the user does not explicitly set a phase in the POM.

        permissionList.add("2aaa");

        allowEmptyPermission.set(true);
        assertTrue(ldapManager.allowEmptyGroupAndRole(user));
        allowEmptyPermission.set(false);
        assertTrue(ldapManager.allowEmptyGroupAndRole(user));

        permissionList.clear();
        permissionList.add("Raaa");

        allowEmptyPermission.set(true);