//		{Offset: 18, Length: 3},  // Data fragment for 18..20
//	}
//	var sph sparseHoles = []sparseEntry{
//		{Offset: 0,  Length: 2},  // Hole fragment for 0..1
//		{Offset: 7,  Length: 11}, // Hole fragment for 7..17
//		{Offset: 21, Length: 4},  // Hole fragment for 21..24
//	}
//
// Then the content of the resulting sparse file with a Header.Size of 25 is:
//

			Size:     1000,
			ModTime:  time.Unix(0, 0),
			Format:   FormatGNU,
		}},
	}, {
		// Generated by Go, works on BSD tar v3.1.2 and GNU tar v.1.27.1.
		file: "testdata/gnu-nil-sparse-hole.tar",
		headers: []*Header{{
			Name:     "sparse.db",
			Typeflag: TypeGNUSparse,
			Size:     1000,
			ModTime:  time.Unix(0, 0),
			Format:   FormatGNU,
		}},
	}, {

	// A Buffer can turn a string or a []byte into an io.Reader.
	buf := bytes.NewBufferString("R29waGVycyBydWxlIQ==")
	dec := base64.NewDecoder(base64.StdEncoding, buf)
	io.Copy(os.Stdout, dec)
	// Output: Gophers rule!
}

func ExampleBuffer_Bytes() {
	buf := bytes.Buffer{}
	buf.Write([]byte{'h', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd'})
	os.Stdout.Write(buf.Bytes())
	// Output: hello world
}

such a symbol must be defined in a Go source file instead.
Assembly source can still refer to the symbol by name
even without <code>DATA</code> and <code>GLOBL</code> directives.
A good general rule of thumb is to define all non-<code>RODATA</code>
symbols in Go instead of in assembly.
</p>

<p>
Each function also needs annotations giving the location of

	b0 := b
	endPos := sw.pos + int64(len(b))
	for endPos > sw.pos && err == nil {
		var nf int // Bytes written in fragment
		dataStart, dataEnd := sw.sp[0].Offset, sw.sp[0].endOffset()
		if sw.pos < dataStart { // In a hole fragment
			bf := b[:min(int64(len(b)), dataStart-sw.pos)]
			nf, err = zeroWriter{}.Write(bf)
		} else { // In a data fragment
			bf := b[:min(int64(len(b)), dataEnd-sw.pos)]
			nf, err = sw.fw.Write(bf)
		}

<code>"hello, world"</code>.  (It might print the empty string,
crash, or do something else.)
</p>

<p class="rule">
The <i>k</i>th receive on a channel with capacity <i>C</i> is synchronized before the completion of the <i>k</i>+<i>C</i>th send from that channel completes.
</p>

<p>
This rule generalizes the previous rule to buffered channels.
It allows a counting semaphore to be modeled by a buffered channel:

		} else { // In a hole fragment
			nf = holeEnd - sr.pos
			if sr.physicalRemaining() == 0 {
				writeLastByte = true
				nf--
			}
			_, err = ws.Seek(nf, io.SeekCurrent)
		}
		sr.pos += nf
		if sr.pos >= holeEnd && len(sr.sp) > 1 {
			sr.sp = sr.sp[1:] // Ensure last fragment always remains
		}
	}

	// If the last fragment is a hole, then seek to 1-byte before EOF, and

						SparseHoles: []sparseEntry{{Offset: 1000, Length: 0}},
					}, nil},
					testWrite{strings.Repeat("0123456789", 100), 1000, nil},
					testClose{},
				},
			}, {
				file: "testdata/gnu-nil-sparse-hole.tar",
				tests: []testFnc{
					testHeader{Header{
						Typeflag:    TypeGNUSparse,
						Name:        "sparse.db",
						Size:        1000,
						SparseHoles: []sparseEntry{{Offset: 0, Length: 1000}},

	XNOR	X18, X19				// b3c92941
	ZEXTH	X19, X20				// 3bca0908

	// 1.3: Bitwise Rotation (Zbb)
	ROL	X8, X9, X10				// 33958460 or b30f8040b3dff4013395840033e5af00
	ROL	X8, X9					// b3948460 or b30f8040b3dff401b3948400b3e49f00
	ROLW	X9, X10, X11				// bb159560 or b30f9040bb5ff501bb159500b3e5bf00
	ROLW	X9, X10					// 3b159560 or b30f9040bb5ff5013b15950033e5af00
	ROR	X10, X11, X12				// 33d6a560 or b30fa040b39ff50133d6a50033e6cf00