anchor.diff:  	File file = new File('./streetEntities/streets.json');
   	File finished = new File('./streetEntities/finished.json');
   	
  -	if(!file.existsSync() || !finished.existsSync())
  +	if(!finished.existsSync())
  +		_createFinishedFile();
  +	
  +	if(!file.existsSync())
   		return tsid;
   	
   	Map streets = JSON.decode(file.readAsStringSync());
  
positive.code: 	finished.writeAsStringSync(JSON.encode(finishedMap));
  }
  
  String getTsidOfUnfilledStreet()
  {
  	String tsid = null;
  
negative.code: 	//save a list of finished and partially finished streets
  	File finished = new File('./streetEntities/finished.json');
  	if(!finished.existsSync())
  		_createFinishedFile();
  	Map finishedMap = JSON.decode(finished.readAsStringSync());
  	int required = params['required'];
  	int complete = params['complete'];
  