anchor.diff:    group('is legal move', () {
       test('first card is always legal move', () {
         Board board = new Board();
  -      for(CardDirection dir in CardUtil.allDirections){
  +      for(CardDirection dir in CardDirection.values){
           expect(Card.values.every((card) => board.isLegalMove(BoardLoc.origin, card, dir)), isTrue);
         }
       });
  
positive.code: 
        BoardLoc testLoc = BoardLoc.origin.neighborLoc(CardDirection.right);
  
        for(CardDirection testDir in CardUtil.allDirections){
          expect(board.isLegalMove(testLoc, Card.pow, testDir), isFalse);
          expect(board.isLegalMove(testLoc, Card.rec, testDir), isFalse);
          expect(board.isLegalMove(testLoc, Card.lab, testDir), isFalse);
  
negative.code: 
        BoardLoc testLoc = BoardLoc.origin.neighborLoc(CardDirection.right);
  
        for(CardDirection testDir in CardDirection.values){
          expect(board.isLegalMove(testLoc, Card.pow, testDir), isTrue);
          expect(board.isLegalMove(testLoc, Card.rec, testDir), isFalse);
          expect(board.isLegalMove(testLoc, Card.lab, testDir), isFalse);
  