docs: def importAddresses(self, addresses):
          """
          Create new L{Person}s for the given names and email addresses.
          Names and emails that already exist are ignored.
  
          @param addresses: a sequence of C{(name, email)} tuples
                            (as returned from L{_parseAddresses})
          @return: the names of people actually imported
          """
          results = []
          for (name, address) in addresses:
              def txn():
                  # Skip names and addresses that already exist.
                  if self.organizer.personByEmailAddress(address) is not None:
                      return
                  # XXX: Needs a better existence check.
                  if self.store.query(Person, Person.name == name).count():
                      return
  
                  try:
                      person = self.organizer.createPerson(name)
                      self.organizer.createContactItem(
                          EmailContactType(self.store), person,
                          dict(email=address))
                  except ValueError, e:
                      # XXX: Granularity required;  see #711 and #2435
                      raise liveform.ConfigurationError(u'%r' % (e,))
                  return person
              results.append(self.store.transact(txn))
          return [p.name for p in results if p is not None]