type Identity struct {
	PrincipalID string `json:"principalId"`
}

// Bucket represents bucket metadata of the event.
type Bucket struct {
	Name          string   `json:"name"`
	OwnerIdentity Identity `json:"ownerIdentity"`
	ARN           string   `json:"arn"`
}

// Object represents object metadata of the event.
type Object struct {
	Key          string            `json:"key"`

		ResponseElements:  respElements,
		S3: event.Metadata{
			SchemaVersion:   "1.0",
			ConfigurationID: "Config",
			Bucket: event.Bucket{
				Name:          args.BucketName,
				OwnerIdentity: event.Identity{PrincipalID: args.ReqParams["principalId"]},
				ARN:           policy.ResourceARNPrefix + args.BucketName,
			},
			Object: event.Object{
				Key:       keyName,
				VersionID: args.Object.VersionID,