ExportedMessage
constructor(id: String, timeIso: Long, senderUserId: ExportedQualifiedId, senderClientId: String, conversationId: ExportedQualifiedId, webPk: Long? = null, lastEditTime: Long? = null, content: ExportedMessage.Content<*>? = null, unknownFields: Map<Int, <Error class: unknown class>> = emptyMap())