anchor.diff:       "Failed requests", 
        "Concurrency Level", 
        "Total transferred",
  -     "Requests per second",
  +     "Requests per second (mean)",
        "Transfer rate"
       ];
       
  
positive.code: import 'dart:io';
  
  void main(args) {
    
    print("Program to extract some data from apache bench log files");
    
    final fname = args[0];
    final file = new File(fname);
    file.readAsString().then((log) {
      final data = log.split("This is ApacheBench,").map((benchrun) {
        if (benchrun.isEmpty) return "";
        
        final lines = benchrun.split("\n").where((line) =>
          line.startsWith("Document Path:") ||
          line.startsWith("Document Length:") ||
  
negative.code:       final rps = lines.where((String line) => line.startsWith("Requests per second:")).first;
        final trans = lines.where((String line) => line.startsWith("Transfer rate:")).first;
        
        // Define some regular expression matchers to read data
        final pingMatcher = new RegExp(r'/ping/\d+');
        final intMatcher = new RegExp(r'\d+');
        final floatMatcher = new RegExp(r'[-+]?(\d*[.])?\d+');
        
        // Some helpers to apply the above matchers
        final getPing = (s) => pingMatcher.firstMatch(s).group(0);
        final getInt = (s) => intMatcher.firstMatch(s).group(0);
        final getFloat = (s) => floatMatcher.firstMatch(s).group(0);
        
        // Return a csv line by applying the matchers
        return
          "${getPing(document)}, " 
          "${getInt(length)}, "
  