old_contents: x = (true, '', 3);
  
  var x1 = +1;
  var x2 = -1;
  var x3 = ~1;
  var x4 = ! x1;
  var x5 = typeof 1;
  var x6 = delete x1;
  
  var y1 = 1 + 3;
  var y2 = 1  3;
  var y3 = 1 / 3;
  var y4 = 1 * 3;
  var y5 = 1 % 3;
  var y6 = y1 in Object;
  var y7 = y1 instanceof Number;
  
  
new_contents: x = (true, '', 3);
  
  var x1 = +1;
  var x2 = -1;
  var x3 = ~1;
  var x4 = ! x1;
  var x5 = typeof 1;
  var x6 = delete x1;
  
  var y1 = 1 + 3;
  var y2 = 1 - 3;
  var y3 = 1 / 3;
  var y4 = 1 * 3;
  var y5 = 1 % 3;
  var y6 = y1 in Object;
  var y7 = y1 instanceof Number;
  
  
subject: Fix a typo