They already know your documentation style based on the portfolio. They are testing your grasp of language fundamentals and various features, and how you can us

They already know your documentation style based on the portfolio. They are testing your grasp of language fundamentals and various features, and how you can use them to solve a simple and common problem. Writing documentation headers in an interview setting should only happen if they explicitly state that you should write them, or after you ask the interviewer if you should be writing them.