rem: return eval(this.header('X-JSON')); } catch (e) {} 
add: var json = this.getHeader('X-JSON'); return json ? eval('(' + json + ')') : null; } catch (e) { return null } 
context:   evalJSON: function() {    try {      return eval(this.header('X-JSON'));    } catch (e) {}  },
meta: 2801	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/2801/7e143d2df37946a5416f0f043869478087652eb6/prototype.js/clean/examples/testcases/prototype.js