* on the fields of TimeoutFuture. This field is slightly different from the fields discussed
   * there: cancel() never reads this field, only writes to it. That makes the race here completely
   * harmless, rather than just 99.99% harmless.
   */
  @LazyInit private @Nullable List<@Nullable Present<V>> values;

  @SuppressWarnings("EmptyList") // ImmutableList doesn't support nullable element types
  CollectionFuture(

    // Now add values near 2^N for lots of values of N.
    for (int exponent : asList(2, 3, 4, 9, 15, 16, 17, 24, 25, 30)) {
      int x = 1 << exponent;
      intValues.add(x, x + 1, x - 1);
    }
    intValues.add(9999).add(10000).add(10001).add(1000000); // near powers of 10
    intValues.add(5792).add(5793); // sqrt(2^25) rounded up and down
    POSITIVE_INTEGER_CANDIDATES = intValues.build();
    NEGATIVE_INTEGER_CANDIDATES =

    checkFromStringCase("[[:]]", 86, "[:]", 86, false);
    checkFromStringCase("x:y:z", 87, "x:y:z", 87, false);
    checkFromStringCase("", 88, "", 88, false);
    checkFromStringCase(":", 99, "", 99, false);
    checkFromStringCase(":123", -1, "", 123, true);
    checkFromStringCase("\nOMG\t", 89, "\nOMG\t", 89, false);
  }

  public void testFromStringParseableIncompleteAddresses() {

    checkFromStringCase("[[:]]", 86, "[:]", 86, false);
    checkFromStringCase("x:y:z", 87, "x:y:z", 87, false);
    checkFromStringCase("", 88, "", 88, false);
    checkFromStringCase(":", 99, "", 99, false);
    checkFromStringCase(":123", -1, "", 123, true);
    checkFromStringCase("\nOMG\t", 89, "\nOMG\t", 89, false);
  }

  private static void checkFromStringCase(
      String hpString,

```
https://yourapi.com/invoices/?callback_url=https://www.external.org/events
```

con un JSON body de:

```JSON
{
    "id": "2expen51ve",
    "customer": "Mr. Richie Rich",
    "total": "9999"
}
```

luego *tu API* procesará la factura y, en algún momento después, enviará un request de callback al `callback_url` (la *API externa*):

```
https://www.external.org/events/invoices/2expen51ve
```

```
https://yourapi.com/invoices/?callback_url=https://www.external.org/events
```

with a JSON body of:

```JSON
{
    "id": "2expen51ve",
    "customer": "Mr. Richie Rich",
    "total": "9999"
}
```

then *your API* will process the invoice, and at some point later, send a callback request to the `callback_url` (the *external API*):

```
https://www.external.org/events/invoices/2expen51ve
```

```
https://yourapi.com/invoices/?callback_url=https://www.external.org/events
```

com um corpo JSON de:

```JSON
{
    "id": "2expen51ve",
    "customer": "Mr. Richie Rich",
    "total": "9999"
}
```

então *sua API* processará a fatura e, em algum momento posterior, enviará um request de callback para o `callback_url` (a *API externa*):

```
https://www.external.org/events/invoices/2expen51ve

```
https://yourapi.com/invoices/?callback_url=https://www.external.org/events
```

с телом JSON:

```JSON
{
    "id": "2expen51ve",
    "customer": "Mr. Richie Rich",
    "total": "9999"
}
```

то *ваш API* обработает счёт и, в какой-то момент позже, отправит запрос обратного вызова на `callback_url` (*внешний API*):

```
https://www.external.org/events/invoices/2expen51ve
```

```
https://yourapi.com/invoices/?callback_url=https://www.external.org/events
```

使用如下 JSON 请求体：

```JSON
{
    "id": "2expen51ve",
    "customer": "Mr. Richie Rich",
    "total": "9999"
}
```

然后，您的 API 就会处理发票，并在某个点之后，发送回调请求至 `callback_url`（外部 API）：

```
https://www.external.org/events/invoices/2expen51ve
```

JSON 请求体包含如下内容：

```JSON
{

```
https://yourapi.com/invoices/?callback_url=https://www.external.org/events
```

mit einem JSON-Körper:

```JSON
{
    "id": "2expen51ve",
    "customer": "Mr. Richie Rich",
    "total": "9999"
}
```

dann verarbeitet *Ihre API* die Rechnung und sendet irgendwann später einen Callback-Request an die `callback_url` (die *externe API*):

```
https://www.external.org/events/invoices/2expen51ve
```