code: function indexesOf(obj, elements) {
        return elements === undefined ? [] : map(elements, function(item) {
          return indexOf(obj, item);
        });
      }
docs: Returns an array of indexes of the first occurrences of the passed elements
  on the passed object.
  
  ```javascript
  var array = [1, 2, 3, 4, 5];
  Ember.EnumerableUtils.indexesOf(array, [2, 5]); // [1, 4]
  
  var fubar = "Fubarr";
  Ember.EnumerableUtils.indexesOf(fubar, ['b', 'r']); // [2, 4]
  ```
  
  @method indexesOf
  @param {Object} obj The object to check for element indexes
  @param {Array} elements The elements to search for on *obj*
  
  @return {Array} An array of indexes.