StartElement{Name{"", "foo"}, []Attr{
			{Name{"space1", "a"}, "space1 value"},
			{Name{"space2", "b"}, "space2 value"},
		}},
	},
	want: `<foo xmlns:_xmlns="xmlns" _xmlns:x="space1"><foo _xmlns:x="space2"><foo xmlns:space1="space1" space1:a="space1 value" xmlns:space2="space2" space2:b="space2 value"></foo></foo><foo xmlns:space1="space1" space1:a="space1 value" xmlns:space2="space2" space2:b="space2 value">`,
}, {

	lastStackScan atomic.Uint64

	// maxStackScan is the amount of allocated goroutine stack space in
	// use by goroutines.
	//
	// This number tracks allocated goroutine stack space rather than used
	// goroutine stack space (i.e. what is actually scanned) because used
	// goroutine stack space is much harder to measure cheaply. By using
	// allocated space, we make an overestimate; this is OK, it's better

//     that would clash without a space, the cutoff must be (in order):
//
//     /*	6
//     &&	6
//     &^	6
//     ++	5
//     --	5
//
//     (Comparison operators always have spaces around them.)
//
//  2. If there is a mix of level 5 and level 4 operators, then the cutoff
//     is 5 (use spaces to distinguish precedence) in Normal mode
//     and 4 (never use spaces) in Compact mode.
//

	// provide addresses outside of those 33 bits. Pick 40 bits
	// as a reasonable balance between address space usage by the
	// page allocator, and flexibility for what mmap'd regions
	// we'll accept for the heap. We can't just move to the full
	// 48 bits because this uses too much address space for older
	// iOS versions.
	// TODO(mknyszek): Once iOS <14 is deprecated, promote ios/arm64

// right places, that is, between arg pairs in which neither is a string.
func TestBlank(t *testing.T) {
	got := Sprint("<", 1, ">:", 1, 2, 3, "!")
	expect := "<1>:1 2 3!"
	if got != expect {
		t.Errorf("got %q expected %q", got, expect)
	}
}

// TestBlankln checks that Sprintln (and hence Println, Fprintln) puts spaces in

			return 0, false
		}

		if uintptr(av) == h.curArena.end {
			// The new space is contiguous with the old
			// space, so just extend the current space.
			h.curArena.end = uintptr(av) + asize
		} else {
			// The new space is discontiguous. Track what
			// remains of the current space and switch to
			// the new space. This should be rare.
			if size := h.curArena.end - h.curArena.base; size != 0 {

	}
}

var trimFuncTests = []struct {
	f        predicate
	in       string
	trimOut  string
	leftOut  string
	rightOut string
}{
	{isSpace, space + " hello " + space,
		"hello",
		"hello " + space,
		space + " hello"},
	{isDigit, "\u0e50\u0e5212hello34\u0e50\u0e51",
		"hello",
		"hello34\u0e50\u0e51",
		"\u0e50\u0e5212hello"},

	return predicate{
		func(r rune) bool {
			return !p.f(r)
		},
		"not " + p.name,
	}
}

var trimFuncTests = []TrimFuncTest{
	{isSpace, space + " hello " + space,
		[]byte("hello"),
		[]byte("hello " + space),
		[]byte(space + " hello")},
	{isDigit, "\u0e50\u0e5212hello34\u0e50\u0e51",
		[]byte("hello"),
		[]byte("hello34\u0e50\u0e51"),
		[]byte("\u0e50\u0e5212hello")},

    // six-per-em space
    assertThat(parse("http://h/\u2006").encodedPath).isEqualTo("/%E2%80%86")
    // figure space
    assertThat(parse("http://h/\u2007").encodedPath).isEqualTo("/%E2%80%87")
    // punctuation space
    assertThat(parse("http://h/\u2008").encodedPath).isEqualTo("/%E2%80%88")
    // thin space
    assertThat(parse("http://h/\u2009").encodedPath).isEqualTo("/%E2%80%89")
    // hair space

		}
		// Handle the case where we have no malloc header.
		scanSize = span.writeHeapBitsSmall(x, dataSize, typ)
	} else {
		if typ.Kind_&abi.KindGCProg != 0 {
			// Allocate space to unroll the gcprog. This space will consist of
			// a dummy _type value and the unrolled gcprog. The dummy _type will
			// refer to the bitmap, and the mspan will refer to the dummy _type.
			if span.spanclass.sizeclass() != 0 {