--- /dev/null
+define( function() {
+
+// A method for quickly swapping in/out CSS properties to get correct calculations.
+return function( elem, options, callback, args ) {
+ var ret, name,
+ old = {};
+
+ // Remember the old values, and insert the new ones
+ for ( name in options ) {
+ old[ name ] = elem.style[ name ];
+ elem.style[ name ] = options[ name ];
+ }
+
+ ret = callback.apply( elem, args || [] );
+
+ // Revert the old values
+ for ( name in options ) {
+ elem.style[ name ] = old[ name ];
+ }
+
+ return ret;
+};
+
+} );