function sub(selector, context) {
			defaults = defaults || callback();

			if (arguments.length === 0) {
				selector = defaults.element;
			}

			if (!context) {
				context = defaults.context;
			}

			return new sub.fn.init(selector, context);
		}
Returns true/false if the current set items matches the selector.

@method is
@param {String} selector Selector to match the elements against.
@return {Boolean} True/false if the current set matches the selector.