code: def has_role(self, role_s):
          
          if self.authorized:
              return self.security_manager.has_role(self.identifiers, role_s)
          msg = 'Cannot check permission when identifiers aren\'t set!'
          raise ValueError(msg)
docs: :param role_s: 1..N role identifiers (strings)
          :type role_s:  Set of Strings
  
          :returns: a set of tuple(s), containing the role and a Boolean
                    indicating whether the user is a member of the Role