private final T value;
    private boolean done;

    SingletonIterator(T value) {
      this.value = value;
    }

    @Override
    public boolean hasNext() {
      return !done;
    }

    @Override
    @ParametricNullness
    public T next() {
      if (done) {
        throw new NoSuchElementException();
      }
      done = true;
      return value;
    }
  }

    * この`dict`の値は`float`型です。（つまり、各項目の価格）

#### `Optional`

また、`Optional`を使用して、変数が`str`のような型を持つことを宣言することもできますが、それは「オプション」であり、`None`にすることもできます。

```Python hl_lines="1 4"
{!../../docs_src/python_types/tutorial009.py!}
```

ただの`str`の代わりに`Optional[str]`を使用することで、エディタは値が常に`str`であると仮定している場合に実際には`None`である可能性があるエラーを検出するのに役立ちます。

#### ジェネリック型

以下のように角括弧で型パラメータを取る型を:

* `List`
* `Tuple`
* `Set`
* `Dict`

	if d == nil || len(d.Cache) <= limit {
		return
	}
	top := hashPath(d.Info.Name).Key()
	topE := d.find(top)
	if topE == nil {
		scannerLogIf(GlobalContext, errors.New("forceCompact: root not found"))
		return
	}
	// If off by 2 orders of magnitude, compact self and log error.
	if len(topE.Children) > dataScannerForceCompactAtFolders {
		// If we still have too many children, compact self.

        });
    }

    /**
     * Unregisters from witness notifications.
     *
     * @param registration the registration to remove
     * @return a future that completes when unregistration is done
     */
    public CompletableFuture<Void> unregister(WitnessRegistration registration) {
        return CompletableFuture.runAsync(() -> {
            try {

        // similar component for re-usage
        if (file != null) {
            if (file.isAbsolute()) {
                // path was already absolute, just normalize file separator and we're done
            } else if (file.getPath().startsWith(File.separator)) {
                // drive-relative Windows path, don't align with project directory but with drive root
                file = file.getAbsoluteFile();

//// tab | Test

Hier einige Dinge, die in HTML-„abbr“-Elemente gepackt sind (einige sind erfunden):

### Das abbr gibt eine vollständige Phrase { #the-abbr-gives-a-full-phrase }

* <abbr title="Getting Things Done – Dinge erledigt bekommen">GTD</abbr>
* <abbr title="less than – kleiner als"><code>lt</code></abbr>
* <abbr title="XML Web Token">XWT</abbr>
* <abbr title="Paralleles Server-Gateway-Interface">PSGI</abbr>

  }

  public void testToArray() {
    // need explicit type parameter to avoid javac warning!?
    List<Boolean> none = Arrays.<Boolean>asList();
    assertThat(Booleans.toArray(none)).isEqualTo(EMPTY);

    List<Boolean> one = Arrays.asList(false);
    assertThat(Booleans.toArray(one)).isEqualTo(ARRAY_FALSE);

    boolean[] array = {false, false, true};

    List<Boolean> three = Arrays.asList(false, false, true);

 * {@link UnsupportedOperationException} when they are not implemented. Most implementations should
 * support either all add operations or none of them, all removal operations or none of them, and if
 * and only if all of these are supported, the {@code setCount} methods as well.
 *
 * <p>A multiset uses {@link Object#equals} to determine whether two instances should be considered

        sb.append("      id: ").append(getId()).append(LS);
        sb.append("      url: ").append(getUrl()).append(LS);
        sb.append("   layout: ").append(layout != null ? layout : "none");

        if (proxy != null) {
            sb.append(LS)
                    .append("    proxy: ")
                    .append(proxy.getHost())
                    .append(':')

    // --------------------------/
    // - Class/Member Variables -/
    // --------------------------/

    /**
     * The one-based line number. The value will be non-positive if
     * unknown.
     */
    private int lineNumber = -1;

    /**
     * The one-based column number. The value will be non-positive
     * if unknown.
     */
    private int columnNumber = -1;

    /**
     * Field source.