*
   * @param reader input source
   * @param charset character set used for encoding chars to bytes
   * @param bufferSize size of internal input and output buffers
   * @throws IllegalArgumentException if bufferSize is non-positive
   */
  ReaderInputStream(Reader reader, Charset charset, int bufferSize) {
    this(
        reader,
        charset
            .newEncoder()

    }

    /**
     * Method read.
     *
     * @param reader a reader object.
     * @param strict a strict object.
     * @return Metadata
     * @throws IOException            IOException if any.
     * @throws XmlPullParserException XmlPullParserException if
     *                                any.
     */
    public Metadata read(Reader reader, boolean strict) throws IOException, XmlPullParserException {
        try {

* Use separate client for leader election in scheduler to avoid starving leader election by regular scheduler operations. ([#53793](https://github.com/kubernetes/kubernetes/pull/53793), [@wojtek-t](https://github.com/wojtek-t))

   * flush all bytes to the underlying resource.
   *
   * @param reader the reader to be closed, or {@code null} in which case this method does nothing
   * @since 17.0
   */
  public static void closeQuietly(@CheckForNull Reader reader) {
    try {
      close(reader, true);
    } catch (IOException impossible) {

)

type scanner struct {
	pos       int64 // position in reader
	ipos      int64 // internal buffer position
	ifill     int64 // internal buffer fill
	end       int64
	buf       [chunk + 1]byte // internal buffer (with a lookback size of 1)
	nbuf      [chunk]byte     // next internal buffer
	fillReq   chan struct{}
	fillReady chan int64
	readerErr error // underlying reader error, if any
}

func newScanner(r io.Reader) *scanner {

    CharSequenceReader reader = new CharSequenceReader(string);
    assertTrue(reader.markSupported());

    assertEquals(string, readFully(reader));
    assertFullyRead(reader);

    // reset and read again
    reader.reset();
    assertEquals(string, readFully(reader));
    assertFullyRead(reader);

    // reset, skip, mark, then read the rest
    reader.reset();
    assertEquals(5, reader.skip(5));

  }

  public void testOpenStream() throws IOException {
    Reader reader = source.openStream();

    StringWriter writer = new StringWriter();
    char[] buf = new char[64];
    int read;
    while ((read = reader.read(buf)) != -1) {
      writer.write(buf, 0, read);
    }
    reader.close();
    writer.close();

    assertExpectedString(writer.toString());
  }

### Typannotationen und Tooling

Sehen wir uns zunächst an, wie Editor, mypy und andere Tools dies sehen würden.

`BaseUser` verfügt über die Basis-Felder. Dann erbt `UserIn` von `BaseUser` und fügt das Feld `Passwort` hinzu, sodass dass es nun alle Felder beider Modelle hat.

Wir annotieren den Funktionsrückgabetyp als `BaseUser`, geben aber tatsächlich eine `UserIn`-Instanz zurück.

type bufReader struct {
	name string
	fn   func(*Reader) string
}

var bufreaders = []bufReader{
	{"1", func(b *Reader) string { return reads(b, 1) }},
	{"2", func(b *Reader) string { return reads(b, 2) }},
	{"3", func(b *Reader) string { return reads(b, 3) }},
	{"4", func(b *Reader) string { return reads(b, 4) }},
	{"5", func(b *Reader) string { return reads(b, 5) }},
	{"7", func(b *Reader) string { return reads(b, 7) }},

  }

  // Returns a Readable that is *not* a Reader.
  private static Readable getChunkedReadable(String input, int chunk) {
    final Reader reader = getChunkedReader(input, chunk);
    return new Readable() {
      @Override
      public int read(CharBuffer cbuf) throws IOException {
        return reader.read(cbuf);
      }
    };
  }

  private static Reader getChunkedReader(String input, final int chunk) {