* provides methods for {@linkplain #startAsync() starting}, {@linkplain #stopAsync() stopping} and
 * {@linkplain #servicesByState inspecting} a collection of {@linkplain Service services}.
 * Additionally, users can monitor state transitions with the {@linkplain Listener listener}
 * mechanism.
 *
 * <p>While it is recommended that service lifecycles be managed via this class, state transitions

 *
 * @author Louis Wasserman
 * @since 33.2.0 (available since 21.0 in guava-jre)
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
@SuppressWarnings("Java7ApiChecker")
@IgnoreJRERequirement // Users will use this only if they're already using streams.
public final class MoreCollectors {

  /*
   * TODO(lowasser): figure out if we can convert this to a concurrent AtomicReference-based
   * collector without breaking j2cl?

import com.google.common.annotations.Beta;
import com.google.errorprone.annotations.CanIgnoreReturnValue;

/**
 * A subinterface of {@link Network} which adds mutation methods. When mutation is not required,
 * users should prefer the {@link Network} interface.
 *
 * @author James Sexton
 * @author Joshua O'Madadhain
 * @param <N> Node parameter type
 * @param <E> Edge parameter type
 * @since 20.0
 */
@Beta

	k.accessToken = accessToken
	k.Unlock()
	return nil
}

// LookupUser lookup user by their userid.
func (k *KeycloakProvider) LookupUser(userid string) (User, error) {
	req, err := http.NewRequest(http.MethodGet, k.adminURL, nil)
	if err != nil {
		return User{}, err
	}
	req.URL.Path = path.Join(req.URL.Path, "realms", k.realm, "users", userid)

	k.Lock()
	accessToken := k.accessToken
	k.Unlock()

## Bug Fixes and Other Changes

*   tf.data:
    *   tf.data users can now represent, get, and set options of TensorFlow
        input pipelines using `tf.data.Options()`, `tf.data.Dataset.options()`,
        and `tf.data.Dataset.with_options()` respectively.
    *   New `tf.data.Dataset.reduce()` API allows users to reduce a finite
        dataset to a single element using a user-provided reduce function.

```JSON
{
  "detail": "Not authenticated"
}
```

### 未激活用户

测试未激活用户，输入以下信息，进行身份验证：

用户名：`alice`

密码：`secret2`

然后，执行 `/users/me` 路径的 `GET` 操作。

显示下列**未激活用户**错误信息：

```JSON
{
  "detail": "Inactive user"
}
```

## 小结

使用本章的工具实现基于 `username` 和 `password` 的完整 API 安全系统。

这些工具让安全系统兼容任何数据库、用户及数据模型。

唯一欠缺的是，它仍然不是真的**安全**。

```json
{
    "user": <string>,
    "maxValiditySeconds": <integer>,
    "claims": <key-value-pairs>
}
```

| Parameter Name     | Value Type                              | Purpose                                                |
|--------------------|-----------------------------------------|--------------------------------------------------------|

   * the Android flavor of Guava). The field is declared with a type of {@code Object} to avoid
   * compatibility problems on Android VMs. The corresponding accessor method, however, can have the
   * more specific return type as long as users are careful to guard calls to it with version checks
   * or reflection: Android VMs ignore the types of elements that aren't used.
   */
  private final @Nullable Object annotatedType;

  Parameter(

   *
   * <p><b>Java 8+ users:</b> use {@link Double#BYTES} instead.
   *
   * @since 10.0
   */
  public static final int BYTES = Double.SIZE / Byte.SIZE;

  /**
   * Returns a hash code for {@code value}; equal to the result of invoking {@code ((Double)
   * value).hashCode()}.
   *
   * <p><b>Java 8+ users:</b> use {@link Double#hashCode(double)} instead.
   *

* `upgrade`: Upgrades