br := NewReader(strings.NewReader("example"))
	br.WriteTo(io.Discard)
	if err := br.UnreadRune(); err == nil {
		t.Error("UnreadRune didn't fail after WriteTo")
	}
}

func TestNoUnreadByteAfterWriteTo(t *testing.T) {
	br := NewReader(strings.NewReader("example"))
	br.WriteTo(io.Discard)
	if err := br.UnreadByte(); err == nil {
		t.Error("UnreadByte didn't fail after WriteTo")
	}
}

	{"ReadByte", func(r *Reader) { r.ReadByte() }},
	{"UnreadRune", func(r *Reader) { r.UnreadRune() }},
	{"Seek", func(r *Reader) { r.Seek(0, io.SeekCurrent) }},
	{"WriteTo", func(r *Reader) { r.WriteTo(&Buffer{}) }},
}

func TestUnreadRuneError(t *testing.T) {
	for _, tt := range UnreadRuneErrorTests {
		reader := NewReader([]byte("0123456789"))
		if _, _, err := reader.ReadRune(); err != nil {

	}
	r.i = abs
	return abs, nil
}

// WriteTo implements the [io.WriterTo] interface.
func (r *Reader) WriteTo(w io.Writer) (n int64, err error) {
	r.prevRune = -1
	if r.i >= int64(len(r.s)) {
		return 0, nil
	}
	b := r.s[r.i:]
	m, err := w.Write(b)
	if m > len(b) {
		panic("bytes.Reader.WriteTo: invalid Write count")
	}
	r.i += int64(m)
	n = int64(m)

	copy(b2, b)
	return b2[:len(b)]
}

// WriteTo writes data to w until the buffer is drained or an error occurs.
// The return value n is the number of bytes written; it always fits into an
// int, but it is int64 to match the io.WriterTo interface. Any error
// encountered during the write is also returned.
func (b *Buffer) WriteTo(w io.Writer) (n int64, err error) {
	b.lastRead = opInvalid

				}
			case testWriteTo:
				f := &testFile{ops: tf.ops}
				got, err := fr.WriteTo(f)
				if _, ok := err.(testError); ok {
					t.Errorf("test %d.%d, WriteTo(): %v", i, j, err)
				} else if got != tf.wantCnt || err != tf.wantErr {
					t.Errorf("test %d.%d, WriteTo() = (%d, %v), want (%d, %v)", i, j, got, err, tf.wantCnt, tf.wantErr)
				}
				if len(f.ops) > 0 {

}

func TestWriteTo(t *testing.T) {
	var buf Buffer
	for i := 3; i < 30; i += 3 {
		s := fillBytes(t, "TestWriteTo (1)", &buf, "", 5, testBytes[0:len(testBytes)/i])
		var b Buffer
		buf.WriteTo(&b)
		empty(t, "TestWriteTo (2)", &b, s, make([]byte, len(testString)))
	}
}

func TestWriteAppend(t *testing.T) {
	var got Buffer
	var want []byte
	for i := 0; i < 1000; i++ {

pkg go/types, method (*Scope) NumChildren() int
pkg go/types, method (*Scope) Parent() *Scope
pkg go/types, method (*Scope) Pos() token.Pos
pkg go/types, method (*Scope) String() string
pkg go/types, method (*Scope) WriteTo(io.Writer, int, bool)
pkg go/types, method (*Selection) Index() []int
pkg go/types, method (*Selection) Indirect() bool
pkg go/types, method (*Selection) Kind() SelectionKind
pkg go/types, method (*Selection) Obj() Object

pkg net/http, var ErrServerClosed error
pkg net/http, var NoBody noBody
pkg net/mail, func ParseDate(string) (time.Time, error)
pkg net, method (*Buffers) Read([]uint8) (int, error)
pkg net, method (*Buffers) WriteTo(io.Writer) (int64, error)
pkg net, method (*Resolver) LookupAddr(context.Context, string) ([]string, error)
pkg net, method (*Resolver) LookupCNAME(context.Context, string) (string, error)

	if err != nil && err != io.EOF {
		tr.err = err
	}
	return n, err
}

// writeTo writes the content of the current file to w.
// The bytes written matches the number of remaining bytes in the current file.
//
// If the current file is sparse and w is an io.WriteSeeker,
// then writeTo uses Seek to skip past holes defined in Header.SparseHoles,
// assuming that skipped regions are filled with NULs.

		buf.Write(fb)
	}
	buf.Write(frag)
	return buf.String(), err
}

// WriteTo implements io.WriterTo.
// This may make multiple calls to the [Reader.Read] method of the underlying [Reader].
// If the underlying reader supports the [Reader.WriteTo] method,
// this calls the underlying [Reader.WriteTo] without buffering.
func (b *Reader) WriteTo(w io.Writer) (n int64, err error) {
	b.lastByte = -1
	b.lastRuneSize = -1