Will getter for private attribute Stopwatch::$sections do the job? IMHO there is little possibility of doing it another way. If it's a good idea I can submit such PR.

@havvg Where are you trying to visualize the Stopwatch data? According to TimeDataCollector it's possible to fetch it using the Debug token (given we are in the profiler or using the debug mode).
If it's possible then I suggest to use this token to fetch the data.

@fabpot Correct me if I'm wrong, but according to the Stopwatch class it supports infinite depth of Section nesting. But the TimeDataCollector supports only one level of nesting. Is it OK?
And another question. How should we behave if we have to fetch Stopwatch events without any knowledge of debug tokens or whatever other knowledge of sections? I don't think that exposing an internal Section class is a good idea since it provides read/write access to the Events. I think that good solution would be to expose a read-only projections of the Section class which would be aware of the hierarchy and events.

@maxromanovsky I'm outside of the framework, just plain Stopwatch Component. I get an instance of the Stopwatch class, and now I want to visualize the data of that Stopwatch: sections, subsections (tree structure) and their respective events. As your link to the TimeDataCollector reads, it's required to have knowledge about the existing sections, otherwise you cannot access them.

My intension of this issue was more like getting feedback on how to actually solve this issue. The Section class is marked for internal use. So I'm not sure, whether exposing the objects Stopwatch::$sections is a way to go. This would ultimately move Section into public namespace (well, it currently is, but you know what I mean). The documentation doesn't reflect, why this class is marked internal.

Re-factoring this into a more open variant is simple (e.g. adding an ImmutableStopwatch, ..), but is it fine, too?

@havvg Let's wait for the decision of Fabien or other guys from Core Team.

I don't really remember why Section was made private back then. I think it makes sense to let anyone introspect/traverse the sections, so making everything "public" makes sense I think.