get result cannot do splitlines

Hi,
on LinuxMint 21.3 Virginia, i adapted in your script in the lines apps and pids.
Then i start your script with
`autohide.py 30&`
and get after the timeout
```
Traceback (most recent call last):
File "/home/USER/bin/autohide.py", line 29, in
_pids = get(["pgrep", app]).splitlines()
AttributeError: 'NoneType' object has no attribute 'splitlines'
```
and the script exits.
Python is python3 v.3.10.6-1~22.04 amd64.
What more data could i collect for you for a possible diagnosis?

--
regards,
-- l0ddej0kk0

Inspect `autohide.py` around line 29 where `_pids = get(["pgrep", app]).splitlines()` is called, then follow the local `get()` helper it uses to confirm when it returns `None`. Reproduce the failure by running the script entrypoint (`autohide.py 30`) with an app name that does not match a running process to verify the same traceback path. Mark it done when the script no longer raises `AttributeError` in that path and continues execution normally.

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