code: def hset(self, hashroot, key, value):
          
          hroot = self.root / hashroot
          if not hroot.is_dir():
              hroot.mkdir()
          hfile = hroot / gethashfile(key)
          d = self.get(hfile, {})
          d.update( {key : value})
          self[hfile] = d
docs: hashed set