tox.ini > [testenv] section > deps: Where is the code that handles deps?

[samuelwhiskeyjohnson]

I realized you can do
deps = -rrequirements.txt
or deps = -r requirements.txt (which was not possible before in tox 3)

Where is the location of the code that handles parsing tox.ini and automatically adds space if you wrote -rrequirements.txt?

[gaborbernat]

https://github.com/tox-dev/tox/blob/main/src%2Ftox%2Ftox_env%2Fpython%2Fpip%2Freq_file.py#L53

[samuelwhiskeyjohnson]

Thanks so much