code: def update(self, permissions):
          
          for k, v in list(permissions.items()):
              self.__setitem__(k, v, reindex=False)
          self.update_index()
docs: Update the permissionset with a dict of namespace<str>:permission<Permission|int|long>
          pairs
  
          Example:
  
              pset.update(
                {
                  "a" : const.PERM_READ,
                  "b" : Permission("b", const.PERM_RW)
                }
              )