docs: def build(self, builder):
          """Build XML by appending to builder"""
          params = dict(OID=self.oid)
          if self.user_type:
              params.update(dict(UserType=self.user_type.value))
          builder.start(self.__class__.__name__, params)
          # build the children
          for child in ('login_name', 'display_name', 'full_name', 'first_name', 'last_name',
                        'organisation'):
              if getattr(self, child) is not None:
                  getattr(self, child).build(builder)
          for address in self.addresses:
              address.build(builder)
          for email in self.emails:
              email.build(builder)
          for phone in self.phones:
              phone.build(builder)
          for location in self.locations:
              location.build(builder)
          builder.end(self.__class__.__name__)