}
		defer conn.Close()
		for i := 0; i < 10; i++ {
			fmt.Fprintf(conn, "%d\n", i)
			time.Sleep(time.Millisecond)
		}
	}()

	wg.Wait()
	if v := netpollWaiters.Load(); v != 0 {
		log.Fatalf("current waiters %v", v)
	}

	fmt.Println("OK")

	s.mu.Unlock()
}

func (s *Weighted) notifyWaiters() {
	for {
		next := s.waiters.Front()
		if next == nil {
			break // No more waiters blocked.
		}

		w := next.Value.(waiter)
		if s.size-s.cur < w.n {
			// Not enough tokens for the next waiter.  We could keep going (to try to
			// find a waiter with a smaller request), but under load that could cause

	// the unlocking goroutine to the waiter at the front of the queue.
	// New arriving goroutines don't try to acquire the mutex even if it appears
	// to be unlocked, and don't try to spin. Instead they queue themselves at
	// the tail of the wait queue.
	//
	// If a waiter receives ownership of the mutex and sees that either
	// (1) it is the last waiter in the queue, or (2) it waited for less than 1 ms,

	}
	// This goroutine has set counter to 0 when waiters > 0.
	// Now there can't be concurrent mutations of state:
	// - Adds must not happen concurrently with Wait,
	// - Wait does not increment waiters if it sees counter == 0.
	// Still do a cheap sanity check to detect WaitGroup misuse.
	if wg.state.Load() != state {
		panic("sync: WaitGroup misuse: Add called concurrently with Wait")
	}
	// Reset waiters count to 0.
	wg.state.Store(0)

		return requestsSent == wantRequestsSent
	}); err != nil {
		t.Fatalf("Failed to wait progress requests, err: %s, want: %d , got %d", err, wantRequestsSent, requestsSent)
	}

	logger.Info("Adding waiters allows progress request to be sent")
	pr.Add()
	wantRequestsSent++
	if err := pollConditionNoChange(pollPeriod, minimalNoChange, pollTimeout, func() bool {
		requestsSent = pr.progressRequestsSentCount.Load()

import "io"

const lineMaxLen = 76

// A Writer is a quoted-printable writer that implements [io.WriteCloser].
type Writer struct {
	// Binary mode treats the writer's input as pure binary and processes end of
	// line bytes as binary data.
	Binary bool

	w    io.Writer
	i    int
	line [78]byte
	cr   bool
}

// NewWriter returns a new [Writer] that writes to w.
func NewWriter(w io.Writer) *Writer {

// NewWriter creates a new byte format writer.
func NewWriter(w io.Writer, v version.Version) (*Writer, error) {
	_, err := version.WriteHeader(w, v)
	return &Writer{w: w, v: v, specs: v.Specs()}, err
}

// WriteEvent writes a single event to the trace wire format stream.
func (w *Writer) WriteEvent(e Event) error {
	// Check version.
	if e.Version != w.v {

// is a *[Writer].
func NewWriter(w io.Writer, order Order, litWidth int) io.WriteCloser {
	return newWriter(w, order, litWidth)
}

func newWriter(dst io.Writer, order Order, litWidth int) *Writer {
	w := new(Writer)
	w.init(dst, order, litWidth)
	return w
}

func (w *Writer) init(dst io.Writer, order Order, litWidth int) {
	switch order {
	case LSB:

	w       *bufio.Writer
}

// NewWriter returns a new Writer that writes to w.
func NewWriter(w io.Writer) *Writer {
	return &Writer{
		Comma: ',',
		w:     bufio.NewWriter(w),
	}
}

// Write writes a single CSV record to w along with any necessary quoting.
// A record is a slice of strings with each string being one field.
// Writes are buffered, so [Writer.Flush] must eventually be called to ensure

	"errors"
	"fmt"
	"io"
	"net/textproto"
	"slices"
	"strings"
)

// A Writer generates multipart messages.
type Writer struct {
	w        io.Writer
	boundary string
	lastpart *part
}

// NewWriter returns a new multipart [Writer] with a random boundary,
// writing to w.
func NewWriter(w io.Writer) *Writer {
	return &Writer{
		w:        w,
		boundary: randomBoundary(),
	}
}