docs: def match_files(self, matched, unmatched):
          """Apply the include and exclude filters to those files in *unmatched*,
          moving those that are included, but not excluded, into the *matched*
          set.
  
          Both *matched* and *unmatched* are sets of unqualified file names."""
          for pattern in self.iter():
              pattern.match_files(matched, unmatched)
              if not unmatched:
                  # Optimization: If we have matched all files already
                  # simply return at this point - nothing else to do
                  break