// returns [<image id, piece name>]
// returns light & dark squares
static LPairS chessPieceImagesFromAGIBlue() {
  ret mapPairsA parseImageSnippetURL(filter(p -> isURL(p.a) && ai_chessPiecesSet().contains(p.b),
    agiBlue_pagesAndValuesForKey(agiBlue_chessPieceImagesSlice(), "is")));
}

// returns only light or dark squares
static LPairS chessPieceImagesFromAGIBlue(Bool lightSquares) {
  if (lightSquares == null) ret chessPieceImagesFromAGIBlue();
  LPairS raw = agiBlue_pagesAndValuesForKey(agiBlue_chessPieceImagesSlice(), "is");
  LPairS squares = agiBlue_pagesAndValuesForKey(agiBlue_chessPieceImagesSlice(), "was on square");
  Set<S> set = asSet(pairsA(filter(squares, p -> lightSquares == chess_isLightSquare(p.b))));
  LPairS filtered = filter(raw, p -> set.contains(p.a));
  ret mapPairsA parseImageSnippetURL(filtered);
}