*/
  public static final byte DEL = 127;

  /**
   * The minimum value of an ASCII character.
   *
   * @since 9.0 (was type {@code int} before 12.0)
   */
  public static final char MIN = 0;

  /**
   * The maximum value of an ASCII character.
   *
   * @since 9.0 (was type {@code int} before 12.0)
   */
  public static final char MAX = 127;

在使用 `Annotated` 之前，请确保先[升级 FastAPI 版本](../deployment/versions.md#upgrading-the-fastapi-versions)到至少 0.95.1。

///

## 在 `q` 参数的类型中使用 `Annotated` { #use-annotated-in-the-type-for-the-q-parameter }

还记得我之前在[Python 类型简介](../python-types.md#type-hints-with-metadata-annotations)中说过可以用 `Annotated` 给参数添加元数据吗？

现在正是与 FastAPI 搭配使用它的时候。🚀

我们之前的类型标注是：

```Python
q: str | None = None
```

我们要做的是用 `Annotated` 把它包起来，变成：

                .actionGet(fessConfig.getIndexHealthTimeout());

        final SuggestSettingsBuilder settingsBuilder = SuggestSettings.builder();
        settingsBuilder.addInitialSettings("search_engine.type", fessConfig.getFesenType());
        settingsBuilder.bulkTimeout(fessConfig.getIndexBulkTimeout());
        settingsBuilder.clusterTimeout(fessConfig.getIndexHealthTimeout());

    assertThrows(IllegalArgumentException.class, () -> Bytes.ensureCapacity(ARRAY1, 1, -1));
  }

  public void testToArray() {
    // need explicit type parameter to avoid javac warning!?
    List<Byte> none = Arrays.<Byte>asList();
    assertThat(Bytes.toArray(none)).isEqualTo(EMPTY);

    List<Byte> one = Arrays.asList((byte) 1);

  public final @Nullable V remove(@Nullable Object rowKey, @Nullable Object columnKey) {
    throw new UnsupportedOperationException();
  }

  /**
   * Serialized type for all ImmutableTable instances. It captures the logical contents and
   * preserves iteration order of all views.
   */
  static final class SerializedForm implements Serializable {
    private final Object[] rowKeys;

import org.apache.maven.eventspy.internal.EventSpyDispatcher;
import org.apache.maven.execution.MavenExecutionRequest;
import org.apache.maven.impl.resolver.MavenSessionBuilderSupplier;
import org.apache.maven.impl.resolver.type.TypeRegistryAdapter;
import org.apache.maven.internal.xml.XmlPlexusConfiguration;
import org.apache.maven.model.ModelBase;
import org.apache.maven.resolver.RepositorySystemSessionFactory;

	"encoding/binary"
	"fmt"
	"hash/crc32"
	"io"
	"io/fs"
	"math/rand"
	"os"
	"strings"
	"testing"
	"testing/fstest"
	"time"
)

// TODO(adg): a more sophisticated test suite

type WriteTest struct {
	Name   string
	Data   []byte
	Method uint16
	Mode   fs.FileMode
}

var writeTests = []WriteTest{
	{
		Name:   "foo",

     * Adds a password validation error message to the messages object based on the error key.
     *
     * @param messages the FessMessages object to add the error to
     * @param errorKey the error key identifying the type of password validation error
     */
    protected void addPasswordValidationError(final FessMessages messages, final String errorKey) {
        switch (errorKey) {
        case "errors.password_length":

```

但因為我們在使用 `Annotated`，我們可以把這個 `Annotated` 的值存到一個變數中，並在多個地方重複使用：

{* ../../docs_src/dependencies/tutorial001_02_an_py310.py hl[12,16,21] *}

/// tip | 提示

這只是標準的 Python，用的是所謂的「型別別名 (type alias)」，其實和 **FastAPI** 本身無關。

但因為 **FastAPI** 是建立在 Python 標準之上（包含 `Annotated`），你就可以在程式碼中使用這個技巧。😎

///

這些依賴依然會如預期運作，而最棒的是「型別資訊會被保留」，代表你的編輯器仍能提供「自動完成」、「即時錯誤」等功能，像 `mypy` 等其他工具也一樣受益。

 *
 * <p>Features:
 * <ul>
 *   <li>Automatic initialization of GCS client</li>
 *   <li>Support for HEAD and GET operations</li>
 *   <li>Content length validation</li>
 *   <li>MIME type detection</li>
 *   <li>Handling of large files through temporary file storage</li>
 *   <li>Object metadata retrieval</li>
 *   <li>Directory listing capabilities</li>
 * </ul>
 *