function constructLevels(options) {
        var levels = [];
        for(var i = 0; i < options.sizes.length; i++) {
            levels.push({
                url: options._id + '/full/' + options.sizes[i].width + ',' +
                    (options.version === 3 ? options.sizes[i].height : '') +
                    '/0/default.' + options.tileFormat,
                width: options.sizes[i].width,
                height: options.sizes[i].height
            });
        }
        return levels.sort(function(a, b) {
            return a.width - b.width;
        });
    }
Build the legacy pyramid URLs (one tile per level)
@function
@param {object} options - infoJson
@throws {Error}