Sie können das bereits in der interaktiven Dokumentation ausprobieren:

<img src="/img/tutorial/security/image03.png">

Wir überprüfen im Moment noch nicht die Gültigkeit des Tokens, aber das ist bereits ein Anfang.

## Zusammenfassung { #recap }

It's called "asynchronous" because the computer / program doesn't have to be "synchronized" with the slow task, waiting for the exact moment that the task finishes, while doing nothing, to be able to take the task result and continue the work.

import org.jspecify.annotations.Nullable;

/**
 * A series of tests that support asserting that collections cannot be modified, either through
 * direct or indirect means.
 *
 * @author Robert Konigsberg
 */
@GwtCompatible
@NullMarked
public class UnmodifiableCollectionTests {

  public static void assertMapEntryIsUnmodifiable(Entry<?, ?> entry) {
    try {

            Document pomDocument = entry.getValue();
            processedPoms.add(pomPath);

            context.info(pomPath + " (checking for Maven 4 compatibility issues)");
            context.indent();

            try {
                boolean hasIssues = false;

                // Apply all compatibility fixes
                hasIssues |= fixUnsupportedCombineChildrenAttributes(pomDocument, context);

```console
$ python -m ensurepip --upgrade

---> 100%
```

</div>

This command will install pip if it is not already installed and also ensures that the installed version of pip is at least as recent as the one available in `ensurepip`.

///

## Add `.gitignore` { #add-gitignore }

If you are using **Git** (you should), add a `.gitignore` file to exclude everything in your `.venv` from Git.

/// tip

import org.jspecify.annotations.Nullable;

/**
 * A series of tests that support asserting that collections cannot be modified, either through
 * direct or indirect means.
 *
 * @author Robert Konigsberg
 */
@GwtCompatible
@NullMarked
public class UnmodifiableCollectionTests {

  public static void assertMapEntryIsUnmodifiable(Entry<?, ?> entry) {
    try {

        return false;
      }
    };

    static final JavaVersion CURRENT;

    static {
      // Under Android, TypeVariable does not implement AnnotatedElement even under recent versions.
      if (AnnotatedElement.class.isAssignableFrom(TypeVariable.class)) {
        if (new TypeCapture<Entry<String, int[][]>>() {}.capture()
            .toString()

Wichtig ist, dass **der erste *Typ-Parameter***, den Sie `Annotated` übergeben, der **tatsächliche Typ** ist. Der Rest sind Metadaten für andere Tools.

Im Moment müssen Sie nur wissen, dass `Annotated` existiert, und dass es Standard-Python ist. 😎

Später werden Sie sehen, wie **mächtig** es sein kann.

/// tip | Tipp

	}
	c := b.buf[b.r]
	b.r++
	b.lastByte = int(c)
	return c, nil
}

// UnreadByte unreads the last byte. Only the most recently read byte can be unread.
//
// UnreadByte returns an error if the most recent method called on the
// [Reader] was not a read operation. Notably, [Reader.Peek], [Reader.Discard], and [Reader.WriteTo] are not
// considered read operations.
func (b *Reader) UnreadByte() error {

     * when hasNext() was called.
     */
    private @Nullable E nextItem;

    /**
     * Index of element returned by most recent call to next. Reset to -1 if this element is deleted
     * by a call to remove.
     */
    private int lastRet;

    Itr() {
      lastRet = -1;
      if (count == 0) nextIndex = -1;
      else {