Hierarchical relations of tracked times

[mneuhaus]

it would be very useful to track the relation of the tracked times.

currently it is not really possible to determine, that a tracked time happened inside another tracked time. This would be very useful for a better understanding of the profiling.

Here are the two files which implement this behavior inside Symfony for inspiration:

• https://github.com/symfony/symfony/blob/master/src/Symfony/Component/HttpKernel/Debug/Stopwatch.php
• https://github.com/symfony/symfony/blob/master/src/Symfony/Component/HttpKernel/Debug/StopwatchEvent.php