code: function recordProxy( old, name ) {
  			return function() {
  				var tracked;
  				try {
  					tracked = JSON.parse(window.localStorage.getItem( shoestring.trackedMethodsKey ) || "{}");
  				} catch (e) {
  					if( e instanceof SyntaxError) {
  						tracked = {};
  					}
  				}
  
  				tracked[ name ] = true;
  				window.localStorage.setItem( shoestring.trackedMethodsKey, JSON.stringify(tracked) );
  
  				return old.apply(this, arguments);
  			};
  		}
docs: return a new function closed over the old implementation