You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: iso2022jp.go
    path of file: ./repos/go-starter-kit/vendor/golang.org/x/text/encoding/japanese
    
    the code of the file until where you have to start completion: // Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package japanese

import (
	"errors"
	"unicode/utf8"

	"golang.org/x/text/encoding"
	"golang.org/x/text/encoding/internal"
	"golang.org/x/text/encoding/internal/identifier"
	"golang.org/x/text/transform"
)

// ISO2022JP is the ISO-2022-JP encoding.
var ISO2022JP encoding.Encoding = &iso2022JP

var iso2022JP = internal.Encoding{
	internal.FuncEncoding{iso2022JPNewDecoder, iso2022JPNewEncoder},
	"ISO-2022-JP",
	identifier.ISO2022JP,
}

func iso2022JPNewDecoder() transform.Transformer {
	return new(iso2022JPDecoder)
}

func iso2022JPNewEncoder() transform.Transformer {
	return new(iso2022JPEncoder)
}

var errInvalidISO2022JP = errors.New("japanese: invalid ISO-2022-JP encoding")

const (
	asciiState = iota
	katakanaState
	jis0208State
	jis0212State
)

const asciiEsc = 0x1b

type iso2022JPDecoder int

func (d *iso2022JPDecoder) Reset() {
	*d = asciiState
}

func (d *iso2022JPDecoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
	r, size := rune(0), 0
loop:
	for ; nSrc < len(src); nSrc += size {
		c0 := src[nSrc]
		if c0 >= utf8.RuneSelf {
			err = errInvalidISO2022JP
			break loop
		}

		if c0 == asciiEsc {
			if nSrc+2 >= len(src) {
				err = transform.ErrShortSrc
				break loop
			}
			size = 3
			c1 := src[nSrc+1]
			c2 := src[nSrc+2]
			switch {
			case c1 == '$' && (c2 == '@' || c2 == 'B'):
				*d = jis0208State
				continue
			case c1 == '$' && c2 == '(':
				if nSrc+3 >= len(src) {
					err = transform.ErrShortSrc
					break loop
				}
				size = 4
				if src[nSrc]+3 == 'D' {
					*d = jis0212State
					continue
				}
			case c1 == '(' && (c2 == 'B' || c2 == 'J'):
				*d = asciiState
				continue
			case c1 == '(' && c2 == 'I':
				*d = katakanaState
				continue
			}
			err = errInvalidISO2022JP
			break loop
		}

		switch *d {
		case asciiState:
			r, size = rune(c0), 1

		case katakanaState:
			if c0 < 0x21 || 0x60 <= c0 {
				err = errInvalidISO2022JP
				break loop
			}
			r, size = rune(c0)+(0xff61-0x21), 1

		default:
			if c0 == 0x0a {
				*d = asc
    
func (e *iso2022JPEncoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
	r, size := rune(0), 0
	for ; nSrc < len(src); nSrc += size {
		r = rune(src[nSrc])

		// Decode a 1-byte rune.
		if r < utf8.RuneSelf {
			size = 1

		} else {
			// Decode a multi-byte rune.
			r, size = utf8.DecodeRune(src[nSrc:])
			if size == 1 {
				// All valid runes of size 1 (those below utf8.RuneSelf) were
				// handled above. We have invalid UTF-8 or we haven't seen the
				// full character yet.
				if !atEOF && !utf8.FullRune(src[nSrc:]) {
					err = transform.ErrShortSrc
					break
				}
			}

			// func init checks that the switch covers all tables.
			//
			// http://encoding.spec.whatwg.org/#iso-2022-jp says that "the index jis0212
			// is not used by the iso-2022-jp encoder due to lack of widespread support".
			//
			// TODO: do we have to special-case U+00A5 and U+203E, as per
			// http://encoding.spec.whatwg.org/#iso-2022-jp
			// Doing so would mean that "\u00a5" would not be preserved
			// after an encode-decode round trip.
			switch {
			case encode0Low <= r && r < encode0High:
				if r = rune(encode0[r-encode0Low]); r>>tableShift == jis0208 {
					goto writeJIS
				}
			case encode1Low <= r && r < encode1High:
				if r = rune(encode1[r-encode1Low]); r>>tableShift == jis0208 {
					goto writeJIS
				}
			case encode2Low <= r && r < encode2High:
				if r = rune(encode2[r-encode2Low]); r>>tableShift == jis0208 {
					goto writeJIS
				}
			case encode3Low <= r && r < encode3High:
				if r = rune(encode3[r-encode3Low]); r>>tableShift == jis0208 {
					goto writeJIS
				}
			case encode4Low <= r && r < encode4High:
				if r = rune(encode4[r-encode4Low]); r>>tableShift == jis0208 {
					goto writeJIS
				}
			case encode5Low <= r && r < encode5High:
				if 0xff61 <= r && r < 0xffa0 {
					goto writeKatakana
				}
				if r = rune(encode5[r-encode5Low]); r>>tableShift == jis0208 {
					goto writeJIS
				}
			}

			// Switch back to ASCII state in case of error so that an ASCII
			// replacement character can be written in the correct state.
			if *e != asciiState {
				if nDst+3 > len(dst) {
					err = transform.ErrShortDst
					break
				}
				*e = asciiState
				dst[nDst+0] = asciiEsc
				dst[nDst+1] = '('
				dst[nDst+2] = 'B'
				nDst += 3
			}
			err = internal.ErrASCIIReplacement
			break
		}

		if *e != asciiState {
			if nDst+4 > len(dst) {
				err = transform.ErrShortDst
				break
			}
			*e = asciiState
			dst[nDst+0] = asciiEsc
			dst[nDst+1] = '('
			dst[nDst+2] = 'B'
			nDst += 3
		} else if nDst >= len(dst) {
			err = transform.ErrShortDst
			break
		}
		dst[nDst] = uint8(r)
		nDst++
		continue

	writeJIS:
		if *e != jis0208State {
			if nDst+5 > len(dst) {
				err = transform.ErrShortDst
				break
			}
			*e = jis0208State
			dst[nDst+0] = asciiEsc
			dst[nDst+1] = '$'
			dst[nDst+2] = 'B'
			nDst += 3
		} else if nDst+2 > len(dst) {
			err = transform.ErrShortDst
			break
		}
		dst[nDst+0] = 0x21 + uint8(r>>codeShift)&codeMask
		dst[nDst+1] = 0x21 + uint8(r)&codeMask
		nDst += 2
		continue

	writeKatakana:
		if *e != katakanaState {
			if nDst+4 > len(dst) {
				err = transform.ErrShortDst
				break
			}
			*e = katakanaState
			dst[nDst+0] = asciiEsc
			dst[nDst+1] = '('
			dst[nDst+2] = 'I'
			nDst += 3
		} else if nDst >= len(dst) {
			err = transform.ErrShortDst
			break
		}
		dst[nDst] = uint8(r - (0xff61 - 0x21))
		nDst++
		continue
	}
	if atEOF && err == nil && *e != asciiState {
		if nDst+3 > len(dst) {
			err = transform.ErrShortDst
		} else {
			*e = asciiState
			dst[nDst+0] = asciiEsc
			dst[nDst+1] = '('
			dst[nDst+2] = 'B'
			nDst += 3
		}
	}
	return nDst, nSrc, err
}