// that broke people during the Go 1.8 testing
			// period. People depend on it being 0 I
			// guess. Maybe retry later. See Issue 18117.
		}
		// For client requests, Request.ContentLength of 0
		// means either actually 0, or unknown. The only way
		// to explicitly say that the ContentLength is zero is
		// to set the Body to nil. But turns out too much code
		// depends on NewRequest returning a non-nil Body,

接下来，使用 **FastAPI** 工具获取用户名与密码。

### `OAuth2PasswordRequestForm` { #oauth2passwordrequestform }

首先，导入 `OAuth2PasswordRequestForm`，然后，在 `/token` *路径操作* 中，用 `Depends` 把该类作为依赖项。

{* ../../docs_src/security/tutorial003_an_py310.py hl[4,78] *}

`OAuth2PasswordRequestForm` 是用以下几项内容声明表单请求体的类依赖项：

* `username`
* `password`
* 可选的 `scope` 字段，由多个空格分隔的字符串组成的长字符串
* 可选的 `grant_type`

            }
        }
        long arrayDuration = System.nanoTime() - arrayStartTime;

        // Set-based lookup should be significantly faster
        // Note: This is a rough check - exact performance depends on JVM, hardware, etc.
        // We expect Set lookup to be at least as fast as array lookup for large datasets
        assertTrue("Set-based lookup should be faster or comparable to array-based lookup for large datasets",

現在用 **FastAPI** 提供的工具來處理。

### `OAuth2PasswordRequestForm` { #oauth2passwordrequestform }

先匯入 `OAuth2PasswordRequestForm`，並在 `/token` 的路徑操作中，搭配 `Depends` 當作依賴使用：

{* ../../docs_src/security/tutorial003_an_py310.py hl[4,78] *}

`OAuth2PasswordRequestForm` 是一個類別型依賴，它宣告了一個表單本文，包含：

- `username`
- `password`
- 可選的 `scope` 欄位，內容是一個由空白分隔的長字串
- 可選的 `grant_type`

// using a PutObject API. PutObjReader encrypts json encoded tier configurations
// if KMS is enabled, otherwise simply yields the json encoded bytes as is.
// Similarly, ObjectOptions value depends on KMS' status.
func (config *TierConfigMgr) configReader(ctx context.Context) (*PutObjReader, *ObjectOptions, error) {
	b, err := config.Bytes()
	if err != nil {
		return nil, nil, err
	}

	return ""
}

// Returns number of errors that occurred the most (incl. nil) and the
// corresponding error value. NB When there is more than one error value that
// occurs maximum number of times, the error value returned depends on how
// golang's map orders keys. This doesn't affect correctness as long as quorum
// value is greater than or equal to simple majority, since none of the equally
// maximal values would occur quorum or more number of times.

//	w.importDir["vendor/golang.org/x/net/route"] = "<goroot>/src/vendor/golang.org/x/net/route"
//
// Since the set of packages that exist depends on context, the result of
// loadImports also depends on context. However, to improve test running time
// the configuration for each environment is cached across runs.
func (w *Walker) loadImports() {
	if w.context == nil {

				if rel.Field.IgnoreMigration {
					continue
				}
				if c := rel.ParseConstraint(); c != nil && c.Schema == dep.Statement.Schema && c.Schema != c.ReferenceSchema {
					dep.Depends = append(dep.Depends, c.ReferenceSchema)
				}

				if rel.Type == schema.HasOne || rel.Type == schema.HasMany {
					beDependedOn[rel.FieldSchema] = true
				}

				if rel.JoinTable != nil {

      TestByteSource okSource = new TestByteSource(bytes);
      assertThrows(IOException.class, () -> okSource.copyTo(new TestByteSink(option)));
      // ensure stream was closed IF it was opened (depends on implementation whether or not it's
      // opened at all if sink.newOutputStream() throws).
      assertTrue(
          "stream not closed when copying to sink with option: " + option,

   * hexadecimal number in lower case.
   *
   * <p>Note that if the output is considered to be a single hexadecimal number, whether this string
   * is big-endian or little-endian depends on the byte order of {@link #asBytes}. This may be
   * surprising for implementations of {@code HashCode} that represent the number in big-endian