Span Issues when merging async genrators

[LukeLalor]

I'm having an issue where I am merging async generators.

Arbitrarily within the generators, more spans are being created. This can get messy and I would like to create a separate span for each generator to group the sub spans.

However, if I merge the generators using aiostream.stream.merge, the span's context gets lost, so the grouping spans disappear deactivate.

I have reduced the issue to a minimal test case that I have posted in stack-overflow.

Does anybody have ideas on what I am doing wrong, if this is a bug, or if there is a workaround I should consider?