write_data_with_id_hashmap.kt

val taskData = HashMap<String, Any>()
taskData["title"] = task.title
taskData["created"] = Timestamp(task.created.time / 1000, 0)

remoteDB.collection("Tasks")
    .document("New task")
    .set(taskData)
    .addOnSuccessListener {
        // Successful write
    }
    .addOnFailureListener {
        // There was an error while writing
    }