AccessLog Sampler - process session ids?

[asfimport]

Sebb (Bug 44420):
The AccessLog Sampler currently processes all logged items, regardless of origin.

It might be useful to be able to process entries based on their session ids (or
some other such marker)

Each thread would only process URLs for a particular id. Would need to determine
how to allocate session ids to threads, and whether the test is run in strict
sequence - i.e. would threads have to wait until their session id appeared?

Or would the sampler just ignore entries which were for a different session id?

How does one know when the session id is no longer valid?

OS: other