VersionID    string            `json:"versionId,omitempty"`
	Sequencer    string            `json:"sequencer"`
}

// Metadata represents event metadata.
type Metadata struct {
	SchemaVersion   string `json:"s3SchemaVersion"`
	ConfigurationID string `json:"configurationId"`
	Bucket          Bucket `json:"bucket"`
	Object          Object `json:"object"`
}

// Source represents client information who triggered the event.