diff --git a/common/stringsupport/string_convert.go b/common/stringsupport/string_convert.go
index 337588479..53ed2ec69 100644
--- a/common/stringsupport/string_convert.go
+++ b/common/stringsupport/string_convert.go
@@ -2,62 +2,14 @@ package stringsupport
 
 import (
 	"bytes"
-	"io/ioutil"
+	"io"
 	"strconv"
 	"strings"
 
-	"golang.org/x/text/encoding"
 	"golang.org/x/text/encoding/japanese"
 	"golang.org/x/text/transform"
 )
 
-// StringConverter is a small helper for encoding/decoding strings.
-type StringConverter struct {
-	Encoding encoding.Encoding
-}
-
-// Decode decodes the given bytes as the set encoding.
-func (sc *StringConverter) Decode(data []byte) (string, error) {
-	decoded, err := ioutil.ReadAll(transform.NewReader(bytes.NewBuffer(data), sc.Encoding.NewDecoder()))
-
-	if err != nil {
-		return "", err
-	}
-
-	return string(decoded), nil
-}
-
-// MustDecode decodes the given bytes as the set encoding. Panics on decode failure.
-func (sc *StringConverter) MustDecode(data []byte) string {
-	decoded, err := sc.Decode(data)
-	if err != nil {
-		panic(err)
-	}
-
-	return decoded
-}
-
-// Encode encodes the given string as the set encoding.
-func (sc *StringConverter) Encode(data string) ([]byte, error) {
-	encoded, err := ioutil.ReadAll(transform.NewReader(bytes.NewBuffer([]byte(data)), sc.Encoding.NewEncoder()))
-
-	if err != nil {
-		return nil, err
-	}
-
-	return encoded, nil
-}
-
-// MustEncode encodes the given string as the set encoding. Panics on encode failure.
-func (sc *StringConverter) MustEncode(data string) []byte {
-	encoded, err := sc.Encode(data)
-	if err != nil {
-		panic(err)
-	}
-
-	return encoded
-}
-
 func UTF8ToSJIS(x string) []byte {
 	e := japanese.ShiftJIS.NewEncoder()
 	xt, _, err := transform.String(e, x)
@@ -69,7 +21,7 @@ func UTF8ToSJIS(x string) []byte {
 
 func SJISToUTF8(b []byte) string {
 	d := japanese.ShiftJIS.NewDecoder()
-	result, err := ioutil.ReadAll(transform.NewReader(bytes.NewReader(b), d))
+	result, err := io.ReadAll(transform.NewReader(bytes.NewReader(b), d))
 	if err != nil {
 		panic(err)
 	}