Autograder requires specific error messages

Hi!

I was just wondering if there might be a way for the autograder to accept more variants of error messages, as it appears that it only accepts certain variations of `Error: no input.` for the edge case with no input and certain variations of `Usage: node guess-flip --call=[heads|tails]` for the edge case when an invalid argument is given, whereas the assignment write-up gives the example of `Error: no input.
Usage: node guess-flip --call=[heads|tails]`. However, I understand that there are limitations to matching more possible outputs with a finite regex expression.

Thank you!