old_contents: function contains(list, elem) {
      return list.indexOf(elem) !== -1;
  }
  
  module.exports = {
      contains: contains
  }
  
new_contents: function fastContains(list, elem) {
      return list.indexOf(elem) !== -1;
  }
  
  function slowContains(list, elem) {
      for (var i = 0; i < list.length; i++) {
          if (list[i] === elem) {
              return true;
          }
      }
      return false;
  }
  
  var contains = Array.prototype.indexOf ? fastContains : slowContains;
  
  module.exports = {
      contains: contains
  }
  
subject: Make contains() actually work in IE8