static L dm_discord_contextAroundLine(long msgID, int i, int j) {
  ret dm_discord_contextAroundLine(dm_call(dm_gazelle_linesCRUD(), 'lineForID, msgID), i, j);
}

static L dm_discord_contextAroundLine(O line, int i, int j) {
  if (line == null) null;
  long channelID = toLong(call(line, 'channelID));
  if (channelID == 0) null;
  L lines = cast dm_call(dm_gazelle_linesCRUD(), 'linesInChannel, channelID);
  int idx = indexOf(lines, line);
  if (idx < 0) ret null with print("Line not found in channel " + channelID);
  ret subList(lines, idx+i, idx+j);
}