func (j *Transaction) UnmarshalJSONFFLexer(fs *fflib.FFLexer, state fflib.FFParseState) error {
	var err error
	currentKey := ffjtTransactionbase
	_ = currentKey
	tok := fflib.FFTok_init
	wantedTok := fflib.FFTok_init
mainparse:
	for {
		tok = fs.Scan()
		if tok == fflib.FFTok_error {
			goto tokerror
		}
		switch state {
		case fflib.FFParse_map_start:
			if tok != fflib.FFTok_left_bracket {
				wantedTok = fflib.FFTok_left_bracket
				goto wrongtokenerror
			}
			state = fflib.FFParse_want_key
			continue
		case fflib.FFParse_after_value:
			if tok == fflib.FFTok_comma {
				state = fflib.FFParse_want_key
			} else if tok == fflib.FFTok_right_bracket {
				goto done
			} else {
				wantedTok = fflib.FFTok_comma
				goto wrongtokenerror
			}
		case fflib.FFParse_want_key:
			if tok == fflib.FFTok_right_bracket {
				goto done
			}
			if tok != fflib.FFTok_string {
				wantedTok = fflib.FFTok_string
				goto wrongtokenerror
			}
			kn := fs.Output.Bytes()
			if len(kn) <= 0 {
				currentKey = ffjtTransactionnosuchkey
				state = fflib.FFParse_want_colon
				goto mainparse
			} else {
				switch kn[0] {
				case 'e':
					if bytes.Equal(ffjKeyTransactionExpiration, kn) {
						currentKey = ffjtTransactionExpiration
						state = fflib.FFParse_want_colon
						goto mainparse
					} else if bytes.Equal(ffjKeyTransactionExtensions, kn) {
						currentKey = ffjtTransactionExtensions
						state = fflib.FFParse_want_colon
						goto mainparse
					}
				case 'o':
					if bytes.Equal(ffjKeyTransactionOperations, kn) {
						currentKey = ffjtTransactionOperations
						state = fflib.FFParse_want_colon
						goto mainparse
					}
				case 'r':
					if bytes.Equal(ffjKeyTransactionRefBlockNum, kn) {
						currentKey = ffjtTransactionRefBlockNum
						state = fflib.FFParse_want_colon
						goto mainparse
					} else if bytes.Equal(ffjKeyTransactionRefBlockPrefix, kn) {
						currentKey = ffjtTransactionRefBlockPrefix
						state = fflib.FFParse_want_colon
						goto mainparse
					}
				}
				if fflib.EqualFoldRight(ffjKeyTransactionExtensions, kn) {
					currentKey = ffjtTransactionExtensions
					state = fflib.FFParse_want_colon
					goto mainparse
				}
				if fflib.EqualFoldRight(ffjKeyTransactionOperations, kn) {
					currentKey = ffjtTransactionOperations
					state = fflib.FFParse_want_colon
					goto mainparse
				}
				if fflib.SimpleLetterEqualFold(ffjKeyTransactionExpiration, kn) {
					currentKey = ffjtTransactionExpiration
					state = fflib.FFParse_want_colon
					goto mainparse
				}
				if fflib.EqualFoldRight(ffjKeyTransactionRefBlockPrefix, kn) {
					currentKey = ffjtTransactionRefBlockPrefix
					state = fflib.FFParse_want_colon
					goto mainparse
				}
				if fflib.EqualFoldRight(ffjKeyTransactionRefBlockNum, kn) {
					currentKey = ffjtTransactionRefBlockNum
					state = fflib.FFParse_want_colon
					goto mainparse
				}
				currentKey = ffjtTransactionnosuchkey
				state = fflib.FFParse_want_colon
				goto mainparse
			}
		case fflib.FFParse_want_colon:
			if tok != fflib.FFTok_colon {
				wantedTok = fflib.FFTok_colon
				goto wrongtokenerror
			}
			state = fflib.FFParse_want_value
			continue
		case fflib.FFParse_want_value:
			if tok == fflib.FFTok_left_brace || tok == fflib.FFTok_left_bracket || tok == fflib.FFTok_integer || tok == fflib.FFTok_double || tok == fflib.FFTok_string || tok == fflib.FFTok_bool || tok == fflib.FFTok_null {
				switch currentKey {
				case ffjtTransactionRefBlockNum:
					goto handle_RefBlockNum
				case ffjtTransactionRefBlockPrefix:
					goto handle_RefBlockPrefix
				case ffjtTransactionExpiration:
					goto handle_Expiration
				case ffjtTransactionOperations:
					goto handle_Operations
				case ffjtTransactionExtensions:
					goto handle_Extensions
				case ffjtTransactionnosuchkey:
					err = fs.SkipField(tok)
					if err != nil {
						return fs.WrapErr(err)
					}
					state = fflib.FFParse_after_value
					goto mainparse
				}
			} else {
				goto wantedvalue
			}
		}
	}
handle_RefBlockNum:
	{
		if tok == fflib.FFTok_null {
		} else {
			tbuf, err := fs.CaptureField(tok)
			if err != nil {
				return fs.WrapErr(err)
			}
			err = j.RefBlockNum.UnmarshalJSON(tbuf)
			if err != nil {
				return fs.WrapErr(err)
			}
		}
		state = fflib.FFParse_after_value
	}
	state = fflib.FFParse_after_value
	goto mainparse
handle_RefBlockPrefix:
	{
		if tok == fflib.FFTok_null {
		} else {
			tbuf, err := fs.CaptureField(tok)
			if err != nil {
				return fs.WrapErr(err)
			}
			err = j.RefBlockPrefix.UnmarshalJSON(tbuf)
			if err != nil {
				return fs.WrapErr(err)
			}
		}
		state = fflib.FFParse_after_value
	}
	state = fflib.FFParse_after_value
	goto mainparse
handle_Expiration:
	{
		if tok == fflib.FFTok_null {
		} else {
			tbuf, err := fs.CaptureField(tok)
			if err != nil {
				return fs.WrapErr(err)
			}
			err = j.Expiration.UnmarshalJSON(tbuf)
			if err != nil {
				return fs.WrapErr(err)
			}
		}
		state = fflib.FFParse_after_value
	}
	state = fflib.FFParse_after_value
	goto mainparse
handle_Operations:
	{
		if tok == fflib.FFTok_null {
		} else {
			tbuf, err := fs.CaptureField(tok)
			if err != nil {
				return fs.WrapErr(err)
			}
			err = j.Operations.UnmarshalJSON(tbuf)
			if err != nil {
				return fs.WrapErr(err)
			}
		}
		state = fflib.FFParse_after_value
	}
	state = fflib.FFParse_after_value
	goto mainparse
handle_Extensions:
	{
		if tok == fflib.FFTok_null {
		} else {
			tbuf, err := fs.CaptureField(tok)
			if err != nil {
				return fs.WrapErr(err)
			}
			err = j.Extensions.UnmarshalJSON(tbuf)
			if err != nil {
				return fs.WrapErr(err)
			}
		}
		state = fflib.FFParse_after_value
	}
	state = fflib.FFParse_after_value
	goto mainparse
wantedvalue:
	return fs.WrapErr(fmt.Errorf("wanted value token, but got token: %v", tok))
wrongtokenerror:
	return fs.WrapErr(fmt.Errorf("ffjson: wanted token: %v, but got token: %v output=%s", wantedTok, tok, fs.Output.String()))
tokerror:
	if fs.BigError != nil {
		return fs.WrapErr(fs.BigError)
	}
	err = fs.Error.ToError()
	if err != nil {
		return fs.WrapErr(err)
	}
	panic("ffjson-generated: unreachable, please report bug.")
done:
	return nil
}
UnmarshalJSONFFLexer fast json unmarshall - template ffjson
package types
import (
	"bytes"
	"fmt"
	fflib "github.com/pquerna/ffjson/fflib/v1"
)
func (j *Transaction) MarshalJSON() ([]byte, error) {
	var buf fflib.Buffer
	if j == nil {
		buf.WriteString("null")
		return buf.Bytes(), nil
	}
	err := j.MarshalJSONBuf(&buf)
	if err != nil {
		return nil, err
	}
	return buf.Bytes(), nil
}
func (j *Transaction) MarshalJSONBuf(buf fflib.EncodingBuffer) error {
	if j == nil {
		buf.WriteString("null")
		return nil
	}
	var err error
	var obj []byte
	_ = obj
	_ = err
	buf.WriteString(`{"ref_block_num":`)
	fflib.FormatBits2(buf, uint64(j.RefBlockNum), 10, false)
	buf.WriteString(`,"ref_block_prefix":`)
	fflib.FormatBits2(buf, uint64(j.RefBlockPrefix), 10, false)
	buf.WriteString(`,"expiration":`)
	{
		obj, err = j.Expiration.MarshalJSON()
		if err != nil {
			return err
		}
		buf.Write(obj)
	}
	buf.WriteString(`,"operations":`)
	{
		obj, err = j.Operations.MarshalJSON()
		if err != nil {
			return err
		}
		buf.Write(obj)
	}
	buf.WriteString(`,"extensions":`)
	{
		obj, err = j.Extensions.MarshalJSON()
		if err != nil {
			return err
		}
		buf.Write(obj)
	}
	buf.WriteByte('}')
	return nil
}
const (
	ffjtTransactionbase = iota
	ffjtTransactionnosuchkey
	ffjtTransactionRefBlockNum
	ffjtTransactionRefBlockPrefix
	ffjtTransactionExpiration
	ffjtTransactionOperations
	ffjtTransactionExtensions
)
var ffjKeyTransactionRefBlockNum = []byte("ref_block_num")
var ffjKeyTransactionRefBlockPrefix = []byte("ref_block_prefix")
var ffjKeyTransactionExpiration = []byte("expiration")
var ffjKeyTransactionOperations = []byte("operations")
var ffjKeyTransactionExtensions = []byte("extensions")
func (j *Transaction) UnmarshalJSON(input []byte) error {
	fs := fflib.NewFFLexer(input)
	return j.UnmarshalJSONFFLexer(fs, fflib.FFParse_map_start)
}