Drop in utility for profiling some code

Profiler.cs

public static class ProfilingService
{
    private static Stopwatch? watch = null;
    public static void StartMeasure()
    {
        lastMillis = 0;
        watch = System.Diagnostics.Stopwatch.StartNew();
        System.Console.WriteLine($"[START]");
    }
    public static void StopMeasure()
    {
        watch.Stop();
        var millis = watch.ElapsedMilliseconds;
        System.Console.WriteLine($"[END] {millis}ms");
    }

    private static long lastMillis = 0;
    public static void Measure(string tag)
    {
        var millis = watch.ElapsedMilliseconds;
        System.Console.WriteLine($"  > [P {tag}] {millis - lastMillis}ms");
        lastMillis = millis;
    }
}