docs: function() {
    var fn = this.__superFunction;
    var self = this;
    var bound = function _super() {
      if (this && this !== self) {
        throw new Error('_super cannot change `this` use _super.unbound');
      }
      return fn && fn.apply(self, arguments);
    };
    return _.extend(bound, { unbound: fn });
  }