code: function(done) {
      rider.group.get(handler, {condition: {name: params.data.name, valid: constant.VALID}}, function(err, gr) {
        if (err) {
          return done(new errors.db.Add());
        }
        if (!_.isEmpty(gr) && !_.isUndefined(gr._id)) {
          return done(new errors.parameter.ParamError("Duplicate key:name"));
        }
        done();
      });
    }
docs: 唯一