Is the function .swap() ever useful?
<p>Browsing through the source of 1.7rc1, line 6625, I've found the <code>.swap</code> function:</p>

<pre><code>// A method for quickly swapping in/out CSS properties to get correct calculations
swap: function( elem, options, callback ) {
    var old = {};

    // Remember the old values, and insert the new ones
    for ( var name in options ) {
        old[ name ] = elem.style[ name ];
        elem.style[ name ] = options[ name ];
    }

    callback.call( elem );

    // Revert the old values
    for ( name in options ) {
        elem.style[ name ] = old[ name ];
    }
}
</code></pre>

<p>I've never seen it used before. Do people actually use it? For what?</p>
