flatten

{
  flatten: function(obj) {
            function flatten(obj) {
                return _.reduce(obj, function(memo, value, key) {
                    if (_.isObject(value)) {
                        _.forEach(flatten(value), function(v, k) {
                            memo[key + "." + k] = v;
                        });
                    } else {
                        memo[key] = value;
                    }

                    return memo;
                }, {})
            }

            return flatten(obj);
        }
        }