function assert( fn ) {
		var el = document.createElement("fieldset");

		try {
			return !!fn( el );
		} catch (e) {
			return false;
		} finally {
			// Remove from its parent by default
			if ( el.parentNode ) {
				el.parentNode.removeChild( el );
			}
			// release memory in IE
			el = null;
		}
	}
Support testing using an element
@param {Function} fn Passed the created element and returns a boolean result