// to operate on list of key values.
type KVS []KV

// Empty - return if kv is empty
func (kvs KVS) Empty() bool {
	return len(kvs) == 0
}

// Clone - returns a copy of the KVS
func (kvs KVS) Clone() KVS {
	return append(make(KVS, 0, len(kvs)), kvs...)
}

// GetWithDefault - returns default value if key not set
func (kvs KVS) GetWithDefault(key string, defaultKVS KVS) string {
	v := kvs.Get(key)

}

// Del - Deletes an entry from the store.
func (store *QueueStore[_]) Del(key Key) error {
	store.Lock()
	defer store.Unlock()
	return store.del(key)
}

// Len returns the entry count.
func (store *QueueStore[_]) Len() int {
	store.RLock()
	l := len(store.entries)
	defer store.RUnlock()
	return l
}

// lockless call
func (store *QueueStore[_]) del(key Key) error {

type Forwarder struct {
	RoundTripper http.RoundTripper
	PassHost     bool
	Logger       func(error)
	ErrorHandler func(http.ResponseWriter, *http.Request, error)

	// internal variables
	rewriter *headerRewriter
}

// NewForwarder creates an instance of Forwarder based on the provided list of configuration options
func NewForwarder(f *Forwarder) *Forwarder {
	f.rewriter = &headerRewriter{}
	if f.RoundTripper == nil {

	Type        JoinType
	Association string
	Subquery    Expression
	Table       string
}

func Has(name string) JoinTarget {
	return JoinTarget{Type: InnerJoin, Association: name}
}

func (jt JoinType) Association(name string) JoinTarget {
	return JoinTarget{Type: jt, Association: name}
}

func (jt JoinType) AssociationFrom(name string, subquery Expression) JoinTarget {

	}
	o = bts
	return
}

// Msgsize returns an upper bound estimate of the number of bytes occupied by the serialized message
func (z BucketOptions) Msgsize() (s int) {
	s = 1 + 8 + msgp.BoolSize + 7 + msgp.BoolSize + 11 + msgp.BoolSize
	return
}

// MarshalMsg implements msgp.Marshaler
func (z ExpirationOptions) MarshalMsg(b []byte) (o []byte, err error) {
	o = msgp.Require(b, z.Msgsize())
	// map header, size 1

)

// Verify if request has JWT.
func isRequestJWT(r *http.Request) bool {
	return strings.HasPrefix(r.Header.Get(xhttp.Authorization), jwtAlgorithm)
}

// Verify if request has AWS Signature Version '4'.
func isRequestSignatureV4(r *http.Request) bool {
	return strings.HasPrefix(r.Header.Get(xhttp.Authorization), signV4Algorithm)
}

// Verify if request has AWS Signature Version '2'.
func isRequestSignatureV2(r *http.Request) bool {

// https://docs.aws.amazon.com/AmazonS3/latest/API/images/s3select-frame-diagram-frame-overview.png
// hence the calculation is made accordingly.
func totalByteLength(headerLength, payloadLength int) int {
	return 4 + 4 + 4 + headerLength + payloadLength + 4
}

func genMessage(header, payload []byte) []byte {
	headerLength := len(header)
	payloadLength := len(payload)
	totalLength := totalByteLength(headerLength, payloadLength)

func (h *headerV7) name() []byte     { return h[000:][:100] }
func (h *headerV7) mode() []byte     { return h[100:][:8] }
func (h *headerV7) uid() []byte      { return h[108:][:8] }
func (h *headerV7) gid() []byte      { return h[116:][:8] }
func (h *headerV7) size() []byte     { return h[124:][:12] }
func (h *headerV7) modTime() []byte  { return h[136:][:12] }
func (h *headerV7) chksum() []byte   { return h[148:][:8] }

	"net/url"
	"os"
	"testing"
	"time"

	"github.com/minio/minio/internal/auth"
	"github.com/minio/pkg/v3/policy"
)

type nullReader struct{}

func (r *nullReader) Read(b []byte) (int, error) {
	return len(b), nil
}

// Test get request auth type.
func TestGetRequestAuthType(t *testing.T) {
	type testCase struct {
		req   *http.Request
		authT authType
	}

	err     error // stateful error
	closer  func()
	creator func() error
}

// newMetacacheReader creates a new cache reader.
// Nothing will be read from the stream yet.
func newMetacacheReader(r io.Reader) *metacacheReader {
	dec := s2DecPool.Get()
	dec.Reset(r)
	mr := msgpNewReader(dec)
	return &metacacheReader{
		mr: mr,
		closer: func() {
			dec.Reset(nil)
			s2DecPool.Put(dec)