The author said they used Claude to decide which E2E tests to run and "Claude never missed a relevant E2E test." How many times did they conduct this experimen

The author said they used Claude to decide which E2E tests to run and "Claude never missed a relevant E2E test." How many times did they conduct this experiment? Over how long time? How did they determine which tests were relevant and that Claude didn't miss them? Did they try it on more than one project? My point was that none of this tells me this will work in general