docs: function uniqBy(dependentKey, propertyKey) {
      return _emberMetalComputed.computed(dependentKey + '.[]', function () {
        var uniq = _emberRuntimeSystemNative_array.A();
        var seen = new _emberMetalEmpty_object.default();
        var list = _emberMetalProperty_get.get(this, dependentKey);
        if (_emberRuntimeUtils.isArray(list)) {
          list.forEach(function (item) {
            var guid = _emberMetalUtils.guidFor(_emberMetalProperty_get.get(item, propertyKey));
            if (!(guid in seen)) {
              seen[guid] = true;
              uniq.push(item);
            }
          });
        }
        return uniq;
      }).readOnly();
    }