.  var humanPlayer, aiPlayer;  humanPlayer = 'x';  aiPlayer = 'o';  var cells = document.querySelectorAll(".cell");    /** Tic Tac Toe game object **/  var TicTacToe = {    checkWinner : function(arr, player){      if(        (arr[0] === player && arr[0] === player && arr[0] === player)||        (arr[0] === player && arr[0] === player && arr[0] === player)||        (arr[0] === player && arr[0] === player && arr[0] === player)||        (arr[0] === player && arr[0] === player && arr[0] === player)||        (arr[0] === player && arr[0] === player && arr[0] === player)||        (arr[0] === player && arr[0] === player && arr[0] === player)||        (arr[0] === player && arr[0] === player && arr[0] === player)||        (arr[0] === player && arr[0] === player && arr[0] === player)      ){        return true;      }      else{        return false;      }    },//checkWinner function.      getAvailableSpots : function(arr){      var spots = [];      for(var i = 0; i < arr.length; i++){        if(arr[i]