rem: const revealed = action.revealedCard; if(revealed) revealed.setFaceDown(); 
add: const cs = action.revealedCards; for(var i = 0; i != cs.length; ++i) cs[i].setFaceDown(); 
context:   undo: function() {    const done = this.actionsDone    const action = done.pop();    this.actionsUndone.push(action);    this.canRedo = true;    this.canUndo = done.length != 0;    gScoreDisplay.value = this.score -= action.score;    this.hintsReady = false;    action.undo();    const revealed = action.revealedCard;    if(revealed) revealed.setFaceDown();    if(this.redealsRemaining==1) gCmdRedeal.removeAttribute("disabled");    if("undoNext" in action && action.undoNext) this.undo();  },
meta: 3385	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/3385/51238e4aeced596a0a6b1b1d3f980bc0d9f2ac0c/cardgame.js/clean/cardgame.js