static GazelleLine dm_discord_importLine(O lineConcept) {
  ret lineConcept == null ? null : nu GazelleLine(
    timestamp := _get created(lineConcept),
    text := _get text(lineConcept),
    msgID := getLong msgID(lineConcept),
    reactions := map(getList(lineConcept, 'reactions), func(O r) -> GazelleReaction {
      nu GazelleReaction(
        userID := getLong(getOpt user(r), 'userID),
        created := _get created(r),
        emoji := _get emoji(r))
    }));
}