Update: Unit tests for f_network().

Update: Unit tests for f_network().

The commit 309f2625e983ef164c52543b492365fe92eed6d5 did not update the unit tests.
The tests currently do not pass due to a regression that will be addressed in a follow up commit.

The referenced commit was rushed so that I could get to the f_string_range_t and related migration.
I didn't bother to review the code or run the unit tests.
I will now have to follow up with a more extensive review and fix any problems.
The unit tests need to also be updated to handle all of the new behavior of the changed function.