from typing import Optional


def say_hi(name: Optional[str]):
    print(f"Hey {name}!")
```

參數 `name` 被標註為 `Optional[str]`，但它並不是可選的；你不能在沒有該參數的情況下呼叫這個函式：

```Python
say_hi()  # 糟了，這會拋出錯誤！😱
```

參數 `name` 仍是必填（不是可選），因為它沒有預設值。不過，`name` 可以接受 `None` 作為值：

```Python
say_hi(name=None)  # 這可行，None 是有效的 🎉
```

好消息是，多數情況下你可以直接用 `|` 來定義型別聯集：

```python
def say_hi(name: str | None):
    print(f"Hey {name}!")

            <id>two-conditions</id>
            <activation>
                <file>
                    <exists>simple.xml</exists>
                </file>
                <property>
                    <name>myproperty</name>
                    <value>test</value>
                </property>
            </activation>
            <properties>
                <profile.file>activated-1</profile.file>
            </properties>

	return count, err
}

func parseKey(k string) (key Key) {
	key.Name = k
	if strings.HasSuffix(k, compressExt) {
		key.Compress = true
		key.Name = strings.TrimSuffix(key.Name, compressExt)
	}
	if key.ItemCount, _ = getItemCount(k); key.ItemCount > 1 {
		key.Name = strings.TrimPrefix(key.Name, fmt.Sprintf("%d:", key.ItemCount))
	}
	if vals := strings.Split(key.Name, "."); len(vals) == 2 {
		key.Extension = "." + vals[1]

        private final String goalPrefix;

        @Nullable
        private final String name;

        PluginInfo(String groupId, String artifactId, String goalPrefix, String name) {
            this.groupId = groupId;
            this.artifactId = artifactId;
            this.goalPrefix = goalPrefix;
            this.name = name;
        }
    }

    private final PluginInfo pluginInfo;

        try {
            var f = target.getClass().getDeclaredField(name);
            f.setAccessible(true);
            return f.get(target);
        } catch (Exception e) {
            fail("access field " + name, e);
            return null;
        }
    }

    private static int invokeProtectedInt(Object target, String name, Object... params) {
        try {

    // Simple FileEntry stub for tests
    private static final class FE implements FileEntry {
        private final String name;

        FE(String name) {
            this.name = name;
        }

        @Override
        public String getName() {
            return name;
        }

        @Override
        public int getType() {
            return 0;
        }

        @Override

t?e=>t(e,this._element):t}_resolvePossibleFunction(t){return v(t,[this._element])}_getPopperConfig(t){const e={placement:t,modifiers:[{name:"flip",options:{fallbackPlacements:this._config.fallbackPlacements}},{name:"offset",options:{offset:this._getOffset()}},{name:"preventOverflow",options:{boundary:this._config.boundary}},{name:"arrow",options:{element:`.${this.constructor.NAME}-arrow`}},{name:"preSetPlacement",enabled:!0,phase:"beforeMain",fn:t=>{this._getTipElement().setAttribute("data-popper-placement",t.st...

    <artifactId>parent</artifactId>
    <version>11-SNAPSHOT</version>
  </parent>

  <groupId>inheritance</groupId>
  <artifactId>inheritance</artifactId>
  <version>11-SNAPSHOT</version>
  <name>Model urls inheritance test child</name>

  <scm child.scm.connection.inherit.append.path="false"
       child.scm.developerConnection.inherit.append.path="false"
       child.scm.url.inherit.append.path="false">

<components namespace="fessCrawler">
	<include path="crawler/container.xml" />

	<component name="contentLengthHelper"
		class="org.codelibs.fess.crawler.helper.ContentLengthHelper" instance="singleton">
		<property name="defaultMaxLength">10485760</property><!-- 10M -->
		<postConstruct name="addMaxLength">
			<arg>"text/html"</arg>
			<arg>2621440</arg><!-- 2.5M -->
		</postConstruct>
	</component>

    }

    return testDir;
  }

  /** Returns the file with the given name under the testdata directory. */
  protected final @Nullable File getTestFile(String name) throws IOException {
    File file = new File(getTestDir(), name);
    if (!file.exists()) {
      URL resourceUrl = IoTestCase.class.getResource("testdata/" + name);
      if (resourceUrl == null) {
        return null;
      }