docs: def no_possible_matches_in_subdirs(self):
          """Returns True if there are no possible matches for any
          subdirectories of this :class:`FileSetState`.
  
          When this :class:FileSetState is used for an 'include', a return of
          `True` means we can exclude all subdirectories."""
          return (not self.parent_has_patterns and self.matched_inherit.empty()
                  and self.matched_and_subdir.empty() and self.unmatched.empty())