receipt.logs.forEach(eventLog => {
   if (eventLog.parsed && eventLog.parsed.event == 'Trace') {
     var funcSig = '0x' + func.signature();
     var parsedArgs = eventLog.parsed.args;
     if (parsedArgs.data.startsWith(funcSig)) {
       called = true;
       retArgs = coder.decodeParams(obj.inputs.map(x => x.type), parsedArgs.data.replace(funcSig, ''));
     }
   }
 });
 contractToPatch[obj.name].decodeReturn = function(returnValue) {
   return coder.decodeParams(obj.outputs.map(x => x.type), returnValue.replace('0x', ''));
 };