code: function (idx, object) {
        if (idx > _emberMetalProperty_get.get(this, 'length')) {
          throw new _emberMetalError.default(OUT_OF_RANGE_EXCEPTION);
        }
  
        this.replace(idx, 0, [object]);
        return this;
      }
docs: This will use the primitive `replace()` method to insert an object at the
  specified index.
  ```javascript
  var colors = ['red', 'green', 'blue'];
  colors.insertAt(2, 'yellow');  // ['red', 'green', 'yellow', 'blue']
  colors.insertAt(5, 'orange');  // Error: Index out of range
  ```
  @method insertAt
  @param {Number} idx index of insert the object at.
  @param {Object} object object to insert
  @return {Ember.Array} receiver
  @public