Function assert

docs/2.2/js/jquery.js:1325–1340

* Support testing using an element * @param {Function} fn Passed the created div and expects a boolean result

( fn )

 * @param {Function} fn Passed the created div and expects a boolean result
 */
function assert( fn ) {
    var div = document.createElement("div");

    try {
        return !!fn( div );
    } catch (e) {
        return false;
    } finally {
        // Remove from its parent by default
        if ( div.parentNode ) {
            div.parentNode.removeChild( div );
        }
        // release memory in IE
        div = null;
    }
}

/**
 * Adds the same handler for all of the specified attrs