pee cup

So I just got a letter when I went to work the other day saying that I need to go to the medecin du travail for my work contract (I've worked there since October...).

I read it over, saw the address, date and time.

Then I saw a sentence that threw me off guard:

"Nous vous prions de bien vouloir munir d'un flacon d'urine..."

Please bring a urine sample.

Say whaaaa???? I have to BRING my own urine? I can't pee there???

Has anyone done this before? Do I really have to sit on the bus holding a cup of my own pee?

Gross...