return sb.toString();
    }

    // ===================================================================================
    //                                                                            Accessor
    //                                                                            ========
    public String getAccessType() {
        checkSpecifiedProperty("accessType");
        return convertEmptyToNull(accessType);

    return (ImmutableList<E>) EMPTY;
  }

  /**
   * Returns an immutable list containing a single element. This list behaves and performs
   * comparably to {@link Collections#singletonList}, but will not accept a null element. It is
   * preferable mainly for consistency and maintainability of your code.
   *
   * @throws NullPointerException if the element is null
   */
  public static <E> ImmutableList<E> of(E e1) {

        final TotalHits totalHits = getClient().get(c -> {
            final SearchRequestBuilder builder = c.prepareSearch(index).setSize(0).setTrackTotalHits(true);
            callback.accept(builder);
            return builder.execute();
        }).getHits().getTotalHits();
        return totalHits != null ? (int) totalHits.value : 0;
    }

  /**
   * A {@link Correspondence} which accepts finite values within {@link #ALLOWED_ERROR} of each
   * other.
   */
  private static final Correspondence<Number, Number> FINITE_QUANTILE_CORRESPONDENCE =
      Correspondence.tolerance(ALLOWED_ERROR);

  /**
   * A {@link Correspondence} which accepts either finite values within {@link #ALLOWED_ERROR} of

    checkNotNull(action);
    for (BiEntry<K, V> entry = firstInKeyInsertionOrder;
        entry != null;
        entry = entry.nextInKeyInsertionOrder) {
      action.accept(entry.key, entry.value);
    }
  }

  @Override
  public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
    checkNotNull(function);

```

支持以下参数：

* `allowed_hosts` - 允许的域名（主机名）列表。`*.example.com` 等通配符域名可以匹配子域名，或使用 `allowed_hosts=["*"]` 允许任意主机名，或省略中间件。

如果传入的请求没有通过验证，则发送 `400` 响应。

## `GZipMiddleware`

处理 `Accept-Encoding` 请求头中包含 `gzip` 请求的 GZip 响应。

中间件会处理标准响应与流响应。

```Python hl_lines="2  6"
{!../../docs_src/advanced_middleware/tutorial003.py!}
```

支持以下参数：

* `minimum_size` - 小于最小字节的响应不使用 GZip。 默认值是 `500`。

   * suggested that listeners are added before the service starts.
   *
   * <p>{@code addListener} guarantees execution ordering across calls to a given listener but not
   * across calls to multiple listeners. Specifically, a given listener will have its callbacks
   * invoked in the same order as the underlying service enters those states. Additionally, at most

        return sb.toString();
    }

    // ===================================================================================
    //                                                                            Accessor
    //                                                                            ========
    public Boolean getAvailable() {
        checkSpecifiedProperty("available");
        return available;
    }

        return sb.toString();
    }

    // ===================================================================================
    //                                                                            Accessor
    //                                                                            ========
    public String getCreatedBy() {
        checkSpecifiedProperty("createdBy");
        return convertEmptyToNull(createdBy);

   * 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.
   */