code: def remove_user_from_acl(self, name, user):
          
          if name not in self._acl:
              return False
          if user in self._acl[name]['allow']:
              self._acl[name]['allow'].remove(user)
          if user in self._acl[name]['deny']:
              self._acl[name]['deny'].remove(user)
          return True
docs: Remove a user from the given acl (both allow and deny).