rem: return this.toArray().join(' '); 
add: return this.expression; 
context:   toString: function() {    return this.toArray().join(' ');  }
meta: 1782	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/1782/a458ebb30ee90b66048c7fd858f5f39957a9be68/prototype.js/clean/webapp/sandbox/scripts/prototype.js