private int getColorTimeInterval(TestReplay TR)
 {
     double testDuration = (TR.getEndTime() - TR.getStartTime()).TotalSeconds;
     if (testDuration <= 8) { return 1; }
     else if (testDuration <= 40) { return 5; }
     else if (testDuration <= 120) { return 15; }
     else { return 30; }
 }