Back Up Message
constructor(id: String = UUID.randomUUID().toString(), piuri: String, from: DID? = null, to: DID? = null, fromPrior: String? = null, body: String, extraHeaders: Map<String, String> = emptyMap(), createdTime: Long? = null, expiresTime: Long? = null, attachments: Array<AttachmentDescriptor> = arrayOf(), thid: String? = null, pthid: String? = null, ack: Array<String>? = emptyArray(), direction: Message.Direction = Message.Direction.RECEIVED)(source)