Are the bathroom fixtures installed yet? Let me know, Tom

Speedball is asking important question...

It is easier to test during construction; it is a bit difficult when walls and floors are finished. Question: what's the reason for the test ?

Back to you... Milo

If the fixtures are installed this will be a difficult task but not impossible.
Purchase a inflatable test ball,(see image)in the correct size and a 10' long chain plus a 10' air hose with two male fittings so it can be inflated.
Remove the toilet and stopper the drains on the tub and vanity.
Now screw on the air hose and shove the test ball asn far as you can. Inflate the ball.
You are now ready to test.
Locate the lavatory roof vent and began filling the vent stack till it overflows. Keep someone down there in case a stopper doesn't hold.
This should give you close to a 10 foot head of water.
Like Milo I want to know the reason for the test. Will you be standing a inspection? Let me know, Tom