anchor.diff:  
       if (i % 1000 == 0 && i > 0) print("INC: $i docs completed");
       lastOffset = i;
  -    if (_SERVER_BASED_CALL) await server.documentGet(source: src, offset: i);
  -    else await analyzer.dartdoc(src, i);
  -
  +    if (_SERVER_BASED_CALL) {
  +      await withTimeOut(server.documentGet(source: src, offset: i));
  +    } else {
  +      await withTimeOut(analyzer.dartdoc(src, i));
  +    }
       if (_PERF_DUMP) print ("PERF: DOCUMENT: ${sw2.elapsedMilliseconds}");
     }
     return sw.elapsedMilliseconds / src.length;
   }
   
  -Future<num> testCompletions(String src, analysis_server.AnalysisServerWrapper wrapper) async {
  +Future<num> testCompletions(
  +    String src, analysis_server.AnalysisServerWrapper wrapper) async {
     lastExecuted = OperationType.Completion;
     Stopwatch sw = new Stopwatch()..start();
     for (int i = 0; i < src.length; i++) {
  
positive.code: 
      if (i % 1000 == 0 && i > 0) print("INC: $i completes");
      lastOffset = i;
      if (_SERVER_BASED_CALL) await server.completeGet(source: src, offset: i);
      else await wrapper.complete(src, i);
      if (_PERF_DUMP) print ("PERF: COMPLETIONS: ${sw2.elapsedMilliseconds}");
    }
    return sw.elapsedMilliseconds / src.length;
  }
  
  Future<num> testFixes(String src, analysis_server.AnalysisServerWrapper wrapper) async {
    lastExecuted = OperationType.Fixes;
    Stopwatch sw = new Stopwatch()..start();
    for (int i = 0; i < src.length; i++) {
  
negative.code:   Stopwatch sw = new Stopwatch()..start();
    int i = 0;
    lastOffset = i;
    await withTimeOut(server.formatGet(source: src, offset: i));
    return sw.elapsedMilliseconds;
  }
  
  Future withTimeOut(Future f) {
    return f.timeout(new Duration (seconds: 30));
  }
  
  String mutate(String src) {
  