docs: function assertOwnProperty (name, msg) {
      if (msg) flag(this, 'message', msg);
      var obj = flag(this, 'object');
      this.assert(
          obj.hasOwnProperty(name)
        , 'expected #{this} to have own property ' + _.inspect(name)
        , 'expected #{this} to not have own property ' + _.inspect(name)
      );
    }