code: def add_last_closed_file(self, fname):
          
          if fname in self.last_closed_files:
              self.last_closed_files.remove(fname)
          self.last_closed_files.insert(0, fname)
          if len(self.last_closed_files) > 10:
              self.last_closed_files.pop(-1)
docs: Add to last closed file list.