srecord noeq G22Tiling<Img extends WidthAndHeight>(Image img) {
  new L<Tile> tiles;

  sclass Tile {
    Rect position;
    
    // Lists of neighbors in all 4 directions (index like NESWDirection)
    // (If only a corner is touching, it's not a neighbor.)
    Cl<Tile>[] neighbors[] = new Cl<Tile>[4];
  }
}