yield := func(v1 V) bool {
			if done {
				return false
			}
			if !yieldNext {
				panic("iter.Pull: yield called again before next")
			}
			yieldNext = false
			v, ok = v1, true
			race.Release(unsafe.Pointer(&racer))
			coroswitch(c)
			race.Acquire(unsafe.Pointer(&racer))
			return !done
		}
		// Recover and propagate panics from seq.
		defer func() {
			if p := recover(); p != nil {
				panicValue = p

	d.state = spongeSqueezing
	d.n = d.rate
	copyOut(d, d.storage[:d.rate])
}

// Write absorbs more data into the hash's state. It panics if any
// output has already been read.
func (d *state) Write(p []byte) (written int, err error) {
	if d.state != spongeAbsorbing {
		panic("sha3: Write after Read")
	}
	written = len(p)

	for len(p) > 0 {
		if d.n == 0 && len(p) >= d.rate {

//
//	config.once.Do(func() { config.init(filename) })
//
// Because no call to Do returns until the one call to f returns, if f causes
// Do to be called, it will deadlock.
//
// If f panics, Do considers it to have returned; future calls of Do return
// without calling f.
func (o *Once) Do(f func()) {
	// Note: Here is an incorrect implementation of Do:
	//
	//	if o.done.CompareAndSwap(0, 1) {
	//		f()

	// -- facts --

	// ImportObjectFact retrieves a fact associated with obj.
	// Given a value ptr of type *T, where *T satisfies Fact,
	// ImportObjectFact copies the value to *ptr.
	//
	// ImportObjectFact panics if called after the pass is complete.
	// ImportObjectFact is not concurrency-safe.
	ImportObjectFact func(obj types.Object, fact Fact) bool

	// ImportPackageFact retrieves a fact associated with package pkg,

		// Need to model this as a read, because there can be
		// several concurrent wg.counter transitions from 0.
		race.Read(unsafe.Pointer(&wg.sema))
	}
	if v < 0 {
		panic("sync: negative WaitGroup counter")
	}
	if w != 0 && delta > 0 && v == int32(delta) {
		panic("sync: WaitGroup misuse: Add called concurrently with Wait")
	}
	if v > 0 || w == 0 {
		return
	}
	// This goroutine has set counter to 0 when waiters > 0.

// MustDeref returns the type of the variable pointed to by t.
// It panics if t's core type is not a pointer.
//
// TODO(adonovan): ideally this would live in typesinternal, but that
// creates an import cycle. Move there when we melt this package down.
func MustDeref(t types.Type) types.Type {
	if ptr, ok := CoreType(t).(*types.Pointer); ok {
		return ptr.Elem()
	}
	panic(fmt.Sprintf("%v is not a pointer", t))

	return z
}

func validateBinaryOperands(x, y *Float) {
	if !debugFloat {
		// avoid performance bugs
		panic("validateBinaryOperands called but debugFloat is not set")
	}
	if len(x.mant) == 0 {
		panic("empty mantissa for x")
	}
	if len(y.mant) == 0 {
		panic("empty mantissa for y")
	}
}

// z = x + y, ignoring signs of x and y for the addition

		t.Errorf("Tick(-1) = %v; want nil", got)
	}
}

// Test that NewTicker panics when given a duration less than zero.
func TestNewTickerLtZeroDuration(t *testing.T) {
	defer func() {
		if err := recover(); err == nil {
			t.Errorf("NewTicker(-1) should have panicked")
		}
	}()
	NewTicker(-1)
}

// Test that Ticker.Reset panics when given a duration less than zero.
func TestTickerResetLtZeroDuration(t *testing.T) {

// If ip is the zero [Addr] or an IPv6 address, As4 panics.
// Note that 0.0.0.0 is not the zero Addr.
func (ip Addr) As4() (a4 [4]byte) {
	if ip.z == z4 || ip.Is4In6() {
		byteorder.BePutUint32(a4[:], uint32(ip.addr.lo))
		return a4
	}
	if ip.z == z0 {
		panic("As4 called on IP zero value")
	}
	panic("As4 called on IPv6 address")
}

	// the directory "net". That is what we want.
	slices.Sort(filenames)
	return filenames, nil
}

// lastBlock returns the last block in the document.
// It panics if the document has no blocks.
func lastBlock(doc *md.Document) md.Block {
	return doc.Blocks[len(doc.Blocks)-1]
}

// addLines adds n lines to the position of b.
// n can be negative.