cookie.go
func (c *Cookie) SetKeyBytes(key []byte) {
	c.key = append(c.key[:0], key...)
}
func (c *Cookie) SetKeyBytes(key []byte) {
	c.key = append(c.key[:0], key...)
}
func ( c * Cookie ) SetKeyBytes ( key [ ] byte ) { c . key = append ( c . key [ : 0 ] , key ... ) }
// SetKeyBytes sets cookie name.
SetKeyBytes sets cookie name .