/**
                             Adds in URL options for paginator links.
                            
                             @module paginator
                             @submodule paginator-url
                             @class Paginator.Url
                             @since 3.10.0
                             */
                            
                            function PaginatorUrl () {}
                            
                            PaginatorUrl.ATTRS = {
                                /**
                                URL to return formatted with the page number. URL uses `Y.Lang.sub` for page number stubstitutions.
                            
                                For example, if the page number is `3`, setting the `pageUrl` to `"?pg={page}"`, will result in `?pg=3`
                            
                                @attribute pageUrl
                                @type String
                                **/
                                pageUrl: {}
                            };
                            
                            PaginatorUrl.prototype = {
                                /**
                                 Returns a formated URL for the previous page.
                                 @method prevPageUrl
                                 @return {String | null} Formatted URL for the previous page, or `null` if there is no previous page.
                                 */
                                prevPageUrl: function () {
                                    return (this.hasPrevPage() && this.formatPageUrl(this.get('page') - 1)) || null;
                                },
                            
                                /**
                                 Returns a formated URL for the next page.
                                 @method nextPageUrl
                                 @return {String | null} Formatted URL for the next page or `null` if there is no next page.
                                 */
                                nextPageUrl: function () {
                                    return (this.hasNextPage() && this.formatPageUrl(this.get('page') + 1)) || null;
                                },
                            
                                /**
                                 Returns a formated URL for the provided page number.
                                 @method formatPageUrl
                                 @param {Number} [page] Page value to be used in the formatted URL. If empty, page will be the value of the `page` ATTRS.
                                 @return {String | null} Formatted URL for the page or `null` if there is not a `pageUrl` set.
                                 */
                                formatPageUrl: function (page) {
                                    var pageUrl = this.get('pageUrl');
                                    if (pageUrl) {
                                        return Y.Lang.sub(pageUrl, {
                                            page: page || this.get('page')
                                        });
                                    }
                                    return null;
                                }
                            };
                            
                            Y.namespace('Paginator').Url = PaginatorUrl;
                            
                            Y.Base.mix(Y.Paginator, [PaginatorUrl]);