3. Dieses `yield from` weist die Funktion an, über das Ding namens `file_like` zu iterieren. Und dann für jeden iterierten Teil, diesen Teil so zurückzugeben, als wenn er aus dieser Generatorfunktion (`iterfile`) stammen würde.

    Es handelt sich also hier um eine Generatorfunktion, die die „generierende“ Arbeit intern auf etwas anderes überträgt.

    try {
      list.add("5");
      fail("transformed list is addable");
    } catch (UnsupportedOperationException expected) {
    }
    list.remove(0);
    assertEquals(asList("2", "3", "4"), list);
    list.remove("3");
    assertEquals(asList("2", "4"), list);
    try {
      list.set(0, "5");
      fail("transformed list is setable");

### Kiểm tra

Mở trình duyệt của bạn tại <a href="http://127.0.0.1:8000" class="external-link" target="_blank">http://127.0.0.1:8000</a>.

Bạn sẽ thấy một JSON response như:

```JSON
{"message": "Hello World"}
```

### Tài liệu tương tác API

Bây giờ tới <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

    plan0.tcpConnectThrowable = IOException("boom!")
    val plan1 = routePlanner.addPlan()
    plan1.tcpConnectDelayNanos = 270.ms // Connect fail at time = 520 ms.
    plan1.tcpConnectThrowable = IOException("boom!")
    val plan2 = routePlanner.addPlan()
    plan2.tcpConnectDelayNanos = 30.ms // Connect fail at time = 530 ms.
    plan2.tcpConnectThrowable = IOException("boom!")
    val plan3 = routePlanner.addPlan()

Bedenken Sie, dass:

```Python
= None
```

oder:

```Python
= Query(default=None)
```

der wichtigste Teil ist, um einen Parameter optional zu machen, da dieses `None` der Defaultwert ist, und das ist es, was diesen Parameter **nicht erforderlich** macht.

Der Teil mit `Union[str, None]` erlaubt es Ihrem Editor, Sie besser zu unterstützen, aber er sagt FastAPI nicht, dass dieser Parameter optional ist.

///

# Comma-separated list of files to include.
# Each item may be enclosed in quotes to gracefully include spaces. Items are trimmed before being loaded.
# If the first character of an item is a question mark, the load will silently fail if the file does not exist.
${includes} = ?"${maven.user.conf}/maven-system.properties", \
              ?"${maven.project.conf}/maven-system.properties"

#
# Settings
#
# Define the default three levels for settings.

# This env is only valid when RBE is available on the selected platform, since
# it enables a derived --config setting.  If RBE is not available (i.e. there
# is no --config setting), bazel would fail and quit. This script does a quick
# check This script checks for such errors early
if ! grep "rbe_$TFCI_BAZEL_TARGET_SELECTING_CONFIG_PREFIX" .bazelrc; then
  cat <<EOF

  /*
   * If you do this test from common.eventbus.EventBusTest, it doesn't actually test the behavior.
   * That is, even if exactly the same method works from inside the common.eventbus package tests,
   * it can fail here.
   */
  public void testAnonymous() {
    AtomicReference<String> holder = new AtomicReference<>();
    AtomicInteger deliveries = new AtomicInteger();
    EventBus bus = new EventBus();
    bus.register(

    writing it has test supersource but no prod supersource.

    GWT happens to use the prod .gwt.xml, so it looks for no supersource for
    tests, either. This causes it to fail to find AtomicLongMapTest.

    Our workaround is to tell GWT that util.concurrent and all other packages
    have prod supersource, even if they have none. GWT is happy to ignore us
    when we specify a nonexistent path.

    writing it has test supersource but no prod supersource.

    GWT happens to use the prod .gwt.xml, so it looks for no supersource for
    tests, either. This causes it to fail to find AtomicLongMapTest.

    Our workaround is to tell GWT that util.concurrent and all other packages
    have prod supersource, even if they have none. GWT is happy to ignore us
    when we specify a nonexistent path.