default:
		return -d
	}
}

// Add returns the time t+d.
func (t Time) Add(d Duration) Time {
	dsec := int64(d / 1e9)
	nsec := t.nsec() + int32(d%1e9)
	if nsec >= 1e9 {
		dsec++
		nsec -= 1e9
	} else if nsec < 0 {
		dsec--
		nsec += 1e9
	}
	t.wall = t.wall&^nsecMask | uint64(nsec) // update nsec
	t.addSec(dsec)
	if t.wall&hasMonotonic != 0 {
		te := t.ext + int64(d)

		}
	}
}

func TestNanosecondsToUTC(t *testing.T) {
	for _, test := range nanoutctests {
		golden := &test.golden
		nsec := test.seconds*1e9 + int64(golden.Nanosecond)
		tm := Unix(0, nsec).UTC()
		newnsec := tm.Unix()*1e9 + int64(tm.Nanosecond())
		if newnsec != nsec {
			t.Errorf("NanosecondsToUTC(%d).Nanoseconds() = %d", nsec, newnsec)
		}
		if !same(tm, golden) {

	if t.wall&hasMonotonic != 0 {
		m2 := uint64(t.ext)
		sign := byte('+')
		if t.ext < 0 {
			sign = '-'
			m2 = -m2
		}
		m1, m2 := m2/1e9, m2%1e9
		m0, m1 := m1/1e9, m1%1e9
		buf := make([]byte, 0, 24)
		buf = append(buf, " m="...)
		buf = append(buf, sign)
		wid := 0
		if m0 != 0 {
			buf = appendInt(buf, int(m0), 0)
			wid = 9
		}

	{-10, -10, "-10"},
	{0, -1, "1"},                      // empty range
	{-1, -100, "1"},                   // empty range
	{-1, 1, "0"},                      // range includes 0
	{-1e9, 0, "0"},                    // range includes 0
	{-1e9, 1e9, "0"},                  // range includes 0
	{-10, -1, "3628800"},              // 10!
	{-20, -2, "-2432902008176640000"}, // -20!
	{-99, -1,

type Timespec struct {
	Sec  int64
	Nsec int64
}

func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }

func NsecToTimespec(nsec int64) (ts Timespec) {
	ts.Sec = nsec / 1e9
	ts.Nsec = nsec % 1e9
	return
}

// TODO(brainman): fix all needed for net

func Accept(fd Handle) (nfd Handle, sa Sockaddr, err error) { return 0, nil, EWINDOWS }

type Timespec struct {
	Sec  int64
	Nsec int64
}

func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }

func NsecToTimespec(nsec int64) (ts Timespec) {
	ts.Sec = nsec / 1e9
	ts.Nsec = nsec % 1e9
	return
}

// TODO(brainman): fix all needed for net

		{"1E", decQuantity(1, 18, DecimalSI)},

		// Decimal exponents
		{"1E-3", decQuantity(1, -3, DecimalExponent)},
		{"1e3", decQuantity(1, 3, DecimalExponent)},
		{"1E6", decQuantity(1, 6, DecimalExponent)},
		{"1e9", decQuantity(1, 9, DecimalExponent)},
		{"1E12", decQuantity(1, 12, DecimalExponent)},
		{"1e15", decQuantity(1, 15, DecimalExponent)},
		{"1E18", decQuantity(1, 18, DecimalExponent)},

		// Nonstandard but still parsable

	// Initial seed required, generate one.
	if r == 0 {
		r = reseed()
	}
	// constants from Numerical Recipes
	r = r*1664525 + 1013904223
	randN = r
	randmu.Unlock()
	return strconv.Itoa(int(1e9 + r%1e9))[1:]
}

// isSameType - compares two object types via reflect.TypeOf
func isSameType(obj1, obj2 interface{}) bool {
	return reflect.TypeOf(obj1) == reflect.TypeOf(obj2)
}

	{Value: &Plain{[3]int{1, 2, 3}}, ExpectXML: `<Plain><V>1</V><V>2</V><V>3</V></Plain>`},
	{Value: ifaceptr(true), MarshalOnly: true, ExpectXML: `<bool>true</bool>`},

	// Test time.
	{
		Value:     &Plain{time.Unix(1e9, 123456789).UTC()},
		ExpectXML: `<Plain><V>2001-09-09T01:46:40.123456789Z</V></Plain>`,
	},

	// A pointer to struct{} may be used to test for an element's presence.
	{
		Value:     &PresenceTest{new(struct{})},

	// easier to reason about for tuning purposes.
	s.sleepController = piController{
		// Tuned loosely via Ziegler-Nichols process.
		kp: 0.3375,
		ti: 3.2e6,
		tt: 1e9, // 1 second reset time.

		// These ranges seem wide, but we want to give the controller plenty of
		// room to hunt for the optimal value.
		min: 0.001,  // 1:1000
		max: 1000.0, // 1000:1
	}