stdouttrace: Refine example

[pellared]

Address #4855 (comment)

FYI @StLeoX @dmathieu @MrAlias

[dashpole]

won't this change the relationship between parent and child spans in the example? e.g. the second multiple will no longer be a child of the first multiply?

[pellared]

won't this change the relationship between parent and child spans in the example? e.g. the second multiple will no longer be a child of the first multiply?

Should it be a child of the first multiply? The operation is done after the previous one. It is a "follow-up action".
Other example if you have HTTP request handling which does "serialization" and then "database insert" then is the "database insert" a child of "serialization"?

[dashpole]

It probably shouldn't be a child of the first multiply.