that controls the execution of certain parts of a Go program.
The environment variable `GODEBUG`
can hold a comma-separated list of these settings.
For example, if a Go program is running in an environment that contains

	GODEBUG=http2client=0,http2server=0

then that Go program will disable the use of HTTP/2 by default in both
the HTTP client and the HTTP server.
It is also possible to set the default `GODEBUG` for a given program

		s = s[i+len(sep):]
	}
}

// Contains reports whether subslice is within b.
func Contains(b, subslice []byte) bool {
	return Index(b, subslice) != -1
}

// ContainsAny reports whether any of the UTF-8-encoded code points in chars are within b.
func ContainsAny(b []byte, chars string) bool {
	return IndexAny(b, chars) >= 0
}

// ContainsRune reports whether the rune is contained in the UTF-8-encoded byte slice b.

	}
	s := buf.String()
	zr, err := NewReader(strings.NewReader(s), int64(len(s)))
	if err != nil {
		t.Fatalf("NewReader: %v", err)
	}
	if got := len(zr.File); got != nFiles {
		t.Fatalf("File contains %d files, want %d", got, nFiles)
	}
	for i := 0; i < nFiles; i++ {
		want := fmt.Sprintf("%d.dat", i)
		if zr.File[i].Name != want {
			t.Fatalf("File(%d) = %q, want %q", i, zr.File[i].Name, want)
		}
	}
}

// For slices, clear sets all elements up to the length of the slice
// to the zero value of the respective element type. If the argument
// type is a type parameter, the type parameter's type set must
// contain only map or slice types, and clear performs the operation
// implied by the type argument.
func clear[T ~[]Type | ~map[Type]Type1](t T)

// The close built-in function closes a channel, which must be either

	if p.peek() != expectedToken {
		p.errorf("expected %s, found %s", expectedMessage, p.next())
	}
}

// have reports whether the remaining tokens (including the current one) contain the specified token.
func (p *Parser) have(token lex.ScanToken) bool {
	for i := p.inputPos; i < len(p.input); i++ {
		if p.input[i].ScanToken == token {
			return true
		}
	}
	return false
}

		f.buf.Next(match[0])
		if err != nil {
			return n, err
		}
	}
	return n, nil
}

func (f *exitCodeFilter) Finish() (int, error) {
	// f.buf could be empty, contain a partial match of exitRe, or
	// contain a full match.
	b := f.buf.Bytes()
	defer f.buf.Reset()
	match := f.exitRe.FindSubmatch(b)
	if len(match) < 2 || match[1] == nil {
		// Not a full match. Flush.

	if strings.Contains(s, "\r") {
		log.Printf("%s: contains CRLFs", filename)
		exitCode = 1
	}
	if filepath.Base(filename) == "go1.4.txt" {
		// No use for blank lines in api files, except go1.4.txt
		// used them in a reasonable way and we should let it be.
	} else if strings.HasPrefix(s, "\n") || strings.Contains(s, "\n\n") {
		log.Printf("%s: contains a blank line", filename)
		exitCode = 1
	}

// At the end of the archive, Next returns the error io.EOF.
//
// If Next encounters a non-local name (as defined by [filepath.IsLocal])
// and the GODEBUG environment variable contains `tarinsecurepath=0`,
// Next returns the header with an [ErrInsecurePath] error.
// A future version of Go may introduce this behavior by default.
// Programs that want to accept non-local names can ignore

	}
	if _, err = writer.Write([]byte(contents)); err != nil {
		t.Fatal(err)
	}
	if err := writer.Close(); err != nil {
		t.Fatal(err)
	}
	// Simple test to make sure PAX extensions are in effect
	if !bytes.Contains(buf.Bytes(), []byte("PaxHeaders.0")) {
		t.Fatal("Expected at least one PAX header to be written.")
	}
	// Test that we can get a long name back out of the archive.
	reader := NewReader(&buf)
	hdr, err = reader.Next()

	}}

	for i, v := range vectors {
		fi := v.h.FileInfo()
		h2, err := FileInfoHeader(fi, "")
		if err != nil {
			t.Error(err)
			continue
		}
		if strings.Contains(fi.Name(), "/") {
			t.Errorf("FileInfo of %q contains slash: %q", v.h.Name, fi.Name())
		}
		name := path.Base(v.h.Name)
		if fi.IsDir() {
			name += "/"
		}
		if got, want := h2.Name, name; got != want {