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: pac_type.go
    path of file: ./repos/plumber/vendor/github.com/jcmturner/gokrb5/v8/pac
    
    the code of the file until where you have to start completion: package pac

import (
	"bytes"
	"errors"
	"fmt"
	"log"

	"github.com/jcmturner/gokrb5/v8/crypto"
	"github.com/jcmturner/gokrb5/v8/iana/keyusage"
	"github.com/jcmturner/gokrb5/v8/types"
	"github.com/jcmturner/rpc/v2/mstypes"
)

const (
	infoTypeKerbValidationInfo     uint32 = 1
	infoTypeCredentials            uint32 = 2
	infoTypePACServerSignatureData uint32 = 6
	infoTypePACKDCSignatureData    uint32 = 7
	infoTypePACClientInfo          uint32 = 10
	infoTypeS4UDelegationInfo      uint32 = 11
	infoTypeUPNDNSInfo             uint32 = 12
	infoTypePACClientClaimsInfo    uint32 = 13
	infoTypePACDeviceInfo          uint32 = 14
	infoTypePACDeviceClaimsInfo    uint32 = 15
)

// PACType implements: https://msdn.microsoft.com/en-us/library/cc237950.aspx
type PACType struct {
	CBuffers           uint32
	Version            uint32
	Buffers            []InfoBuffer
	Data               []byte
	KerbValidationInfo *KerbValidationInfo
	CredentialsInfo    *CredentialsInfo
	ServerChecksum     *SignatureData
	KDCChecksum        *SignatureData
	ClientInfo         *ClientInfo
	S4UDelegationInfo  *S4UDelegationInfo
	UPNDNSInfo         *UPNDNSInfo
	ClientClaimsInfo   *ClientClaimsInfo
	DeviceInfo         *DeviceInfo
	DeviceClaimsInfo   *DeviceClaimsInfo
	ZeroSigData        []byte
}

// InfoBuffer implements the PAC Info Buffer: https://msdn.microsoft.com/en-us/library/cc237954.aspx
type InfoBuffer struct {
	ULType       uint32 // A 32-bit unsigned integer in little-endian form
    
func (pac *PACType) ProcessPACInfoBuffers(key types.EncryptionKey, l *log.Logger) error {
	for _, buf := range pac.Buffers {
		p := make([]byte, buf.CBBufferSize, buf.CBBufferSize)
		copy(p, pac.Data[int(buf.Offset):int(buf.Offset)+int(buf.CBBufferSize)])
		switch buf.ULType {
		case infoTypeKerbValidationInfo:
			if pac.KerbValidationInfo != nil {
				//Must ignore subsequent buffers of this type
				continue
			}
			var k KerbValidationInfo
			err := k.Unmarshal(p)
			if err != nil {
				return fmt.Errorf("error processing KerbValidationInfo: %v", err)
			}
			pac.KerbValidationInfo = &k
		case infoTypeCredentials:
			// Currently PAC parsing is only useful on the service side in gokrb5
			// The CredentialsInfo are only useful when gokrb5 has implemented RFC4556 and only applied on the client side.
			// Skipping CredentialsInfo - will be revisited under RFC4556 implementation.
			continue
			//if pac.CredentialsInfo != nil {
			//	//Must ignore subsequent buffers of this type
			//	continue
			//}
			//var k CredentialsInfo
			//err := k.Unmarshal(p, key) // The encryption key used is the AS reply key only available to the client.
			//if err != nil {
			//	return fmt.Errorf("error processing CredentialsInfo: %v", err)
			//}
			//pac.CredentialsInfo = &k
		case infoTypePACServerSignatureData:
			if pac.ServerChecksum != nil {
				//Must ignore subsequent buffers of this type
				continue
			}
			var k SignatureData
			zb, err := k.Unmarshal(p)
			copy(pac.ZeroSigData[int(buf.Offset):int(buf.Offset)+int(buf.CBBufferSize)], zb)
			if err != nil {
				return fmt.Errorf("error processing ServerChecksum: %v", err)
			}
			pac.ServerChecksum = &k
		case infoTypePACKDCSignatureData:
			if pac.KDCChecksum != nil {
				//Must ignore subsequent buffers of this type
				continue
			}
			var k SignatureData
			zb, err := k.Unmarshal(p)
			copy(pac.ZeroSigData[int(buf.Offset):int(buf.Offset)+int(buf.CBBufferSize)], zb)
			if err != nil {
				return fmt.Errorf("error processing KDCChecksum: %v", err)
			}
			pac.KDCChecksum = &k
		case infoTypePACClientInfo:
			if pac.ClientInfo != nil {
				//Must ignore subsequent buffers of this type
				continue
			}
			var k ClientInfo
			err := k.Unmarshal(p)
			if err != nil {
				return fmt.Errorf("error processing ClientInfo: %v", err)
			}
			pac.ClientInfo = &k
		case infoTypeS4UDelegationInfo:
			if pac.S4UDelegationInfo != nil {
				//Must ignore subsequent buffers of this type
				continue
			}
			var k S4UDelegationInfo
			err := k.Unmarshal(p)
			if err != nil {
				l.Printf("could not process S4U_DelegationInfo: %v", err)
				continue
			}
			pac.S4UDelegationInfo = &k
		case infoTypeUPNDNSInfo:
			if pac.UPNDNSInfo != nil {
				//Must ignore subsequent buffers of this type
				continue
			}
			var k UPNDNSInfo
			err := k.Unmarshal(p)
			if err != nil {
				l.Printf("could not process UPN_DNSInfo: %v", err)
				continue
			}
			pac.UPNDNSInfo = &k
		case infoTypePACClientClaimsInfo:
			if pac.ClientClaimsInfo != nil || len(p) < 1 {
				//Must ignore subsequent buffers of this type
				continue
			}
			var k ClientClaimsInfo
			err := k.Unmarshal(p)
			if err != nil {
				l.Printf("could not process ClientClaimsInfo: %v", err)
				continue
			}
			pac.ClientClaimsInfo = &k
		case infoTypePACDeviceInfo:
			if pac.DeviceInfo != nil {
				//Must ignore subsequent buffers of this type
				continue
			}
			var k DeviceInfo
			err := k.Unmarshal(p)
			if err != nil {
				l.Printf("could not process DeviceInfo: %v", err)
				continue
			}
			pac.DeviceInfo = &k
		case infoTypePACDeviceClaimsInfo:
			if pac.DeviceClaimsInfo != nil {
				//Must ignore subsequent buffers of this type
				continue
			}
			var k DeviceClaimsInfo
			err := k.Unmarshal(p)
			if err != nil {
				l.Printf("could not process DeviceClaimsInfo: %v", err)
				continue
			}
			pac.DeviceClaimsInfo = &k
		}
	}

	if ok, err := pac.verify(key); !ok {
		return err
	}

	return nil
}