}

var errUnreadByte = errors.New("bytes.Buffer: UnreadByte: previous operation was not a successful read")

// UnreadByte unreads the last byte returned by the most recent successful
// read operation that read at least one byte. If a write has happened since
// the last read, if the last read returned an error, or if the read read zero
// bytes, UnreadByte returns an error.
func (b *Buffer) UnreadByte() error {

	// check not at EOF
	b.WriteString("abcdefghijklmnopqrstuvwxyz")

	// after unsuccessful read
	if n, err := b.Read(nil); n != 0 || err != nil {
		t.Fatalf("Read(nil) = %d,%v; want 0,nil", n, err)
	}
	if err := b.UnreadByte(); err == nil {
		t.Fatal("UnreadByte after Read(nil): got no error")
	}

	// after successful read
	if _, err := b.ReadBytes('m'); err != nil {
		t.Fatalf("ReadBytes: %v", err)
	}

			link(path, link, callback) { callback(enosys()); },
			lstat(path, callback) { callback(enosys()); },
			mkdir(path, perm, callback) { callback(enosys()); },
			open(path, flags, mode, callback) { callback(enosys()); },
			read(fd, buffer, offset, length, position, callback) { callback(enosys()); },
			readdir(path, callback) { callback(enosys()); },
			readlink(path, callback) { callback(enosys()); },
			rename(from, to, callback) { callback(enosys()); },

	}
	return ast1
}

func sourceLine(n ast.Node) int {
	return fset.Position(n.Pos()).Line
}

// ParseGo populates f with information learned from the Go source code
// which was read from the named file. It gathers the C preamble
// attached to the import "C" comment, a list of references to C.xxx,
// a list of exported functions, and the actual AST, to be rewritten and
// printed.

*/
package main

/*
Implementation details.

Cgo provides a way for Go programs to call C code linked into the same
address space. This comment explains the operation of cgo.

Cgo reads a set of Go source files and looks for statements saying
import "C". If the import has a doc comment, that comment is
taken as literal C code to be used as a preamble to any C code

	}
	defer lock.Close()
	if err := syscall.Flock(int(lock.Fd()), syscall.LOCK_EX); err != nil {
		return 0, err
	}

	// In case we're booting a device or emulator alongside all.bash, wait for
	// it to be ready. adb wait-for-device is not enough, we have to
	// wait for sys.boot_completed.
	if err := adb("wait-for-device", "exec-out", "while [[ -z $(getprop sys.boot_completed) ]]; do sleep 1; done;"); err != nil {
		return 0, err
	}

		Method: Deflate,
		Mode:   0755 | fs.ModeDevice | fs.ModeCharDevice,
	},
}

func TestWriter(t *testing.T) {
	largeData := make([]byte, 1<<17)
	if _, err := rand.Read(largeData); err != nil {
		t.Fatal("rand.Read failed:", err)
	}
	writeTests[1].Data = largeData
	defer func() {
		writeTests[1].Data = nil
	}()

	// write a zip file
	buf := new(bytes.Buffer)
	w := NewWriter(buf)

// Read is never called with an empty buffer.
type testNonEmptyReader struct{ io.Reader }

func (r testNonEmptyReader) Read(b []byte) (int, error) {
	if len(b) == 0 {
		return 0, errors.New("unexpected empty Read call")
	}
	return r.Reader.Read(b)
}

func TestFileReader(t *testing.T) {
	type (
		testRead struct { // Read(cnt) == (wantStr, wantErr)
			cnt     int

	PAXRecords map[string]string

	// Format specifies the format of the tar header.
	//
	// This is set by Reader.Next as a best-effort guess at the format.
	// Since the Reader liberally reads some non-compliant files,
	// it is possible for this to be FormatUnknown.
	//
	// If the format is unspecified when Writer.WriteHeader is called,
	// then it uses the first format (in the order of USTAR, PAX, GNU)

// the [Scanner] returns it to the user. If the token is nil, the
// Scanner reads more data and continues scanning; if there is no more
// data--if atEOF was true--the [Scanner] returns. If the data does not
// yet hold a complete token, for instance if it has no newline while
// scanning lines, a [SplitFunc] can return (0, nil, nil) to signal the
// [Scanner] to read more data into the slice and try again with a