accounts/abi: remove function Unpack2 (ethereum#20830)

accounts/abi/abi.go

@@ -250,10 +250,10 @@ func UnpackRevert(data []byte) (string, error) {
 	if !bytes.Equal(data[:4], revertSelector) {
 		return "", errors.New("invalid data for unpacking")
 	}
+	var reason string
 	typ, _ := NewType("string", "", nil)
-	unpacked, err := (Arguments{{Type: typ}}).Unpack2(data[4:])
-	if err != nil {
+	if err := (Arguments{{Type: typ}}).Unpack(&reason, data[4:]); err != nil {
 		return "", err
 	}
-	return unpacked[0].(string), nil
+	return reason, nil
 }

accounts/abi/argument.go

@@ -18,7 +18,6 @@ package abi
 
 import (
 	"encoding/json"
-	"errors"
 	"fmt"
 	"reflect"
 	"strings"
@@ -113,17 +112,6 @@ func (arguments Arguments) Unpack(v interface{}, data []byte) error {
 	return arguments.unpackAtomic(v, marshalledValues[0])
 }
 
-// Unpack2 performs the operation hexdata -> Go format.
-func (arguments Arguments) Unpack2(data []byte) ([]interface{}, error) {
-	if len(data) == 0 {
-		if len(arguments.NonIndexed()) != 0 {
-			return nil, errors.New("abi: attempting to unmarshall an empty string while arguments are expected")
-		}
-		return make([]interface{}, 0), nil
-	}
-	return arguments.UnpackValues(data)
-}
-
 // UnpackIntoMap performs the operation hexdata -> mapping of argument name to argument value
 func (arguments Arguments) UnpackIntoMap(v map[string]interface{}, data []byte) error {
 	// Make sure map is not nil