docs: def update(self, addresses):
          """Updating with a set of addresses.
          """
          if isinstance(addresses, six.string_types):
              addresses = [addresses, ]
          s0_, s1_ = set(self.addresses), set(addresses)
          sr_, sa_ = s0_.difference(s1_), s1_.difference(s0_)
          for a__ in sr_:
              self.remove(a__)
          for a__ in sa_:
              self.add(a__)
          return bool(sr_ or sa_)