How to run only one chosen unittest

[madwebness]

Been banging my head with ChaptGPT on this one, it just couldn't 
figure it out how to run only a particular unittest with `dub 
test`, so I have to ask.

I only use standard `unittest {}`, no libraries. It's quite often 
that I just want to run one single unit test - or, at the very 
least, only tests in one particular module (if one test isn't 
possible).

To give you an idea from other languages, Iin Go + Ginkgo this 
would be:

```
It("should run this one", Label("onlythis"), func() { ...
```
in Ruby / rspec it'd be something like:

```
rspec path/to/test.rb:25
```
where 25 is the line number of unit test starts.

I understand that even in Go or Ruby - those are the testing 
libraries in my examples, not something native to the language, 
but I was still wondering if something like that is possible in 
D. I wouldn't even mind writing some short Bash script that would 
temporarily manipulate `dub.json` or something like that - to 
achieve what I want. The number of unittests in my codebase is 
getting larger and I feel it might be the right time to address 
this problem.

Would appreciate some any ideas here.