static void mergeLinesIntoGlyphTeachLog(S snippetID, S text) {
  L<S> lines = map afterSquareBracketStuff(unquoteWholeLog(text));
  Set<S> existing = asCISet(map afterSquareBracketStuff(scanLog(glyphTeachLog())));
  //pnl(lines);
  //pnl(existing);
  lines = listWithoutSet(lines, existing);
  if (nempty(lines)) {
    print("Have " + n2(lines, "new line") + " for glyph log.");
    for (S line : lines)
      logQuoted(glyphTeachLog(), "[" + snippetID + "] " + line);
  }
}