def with_organisation(self, organisation):
if organisation is None:<EOL><INDENT>organisation = '<STR_LIT>'<EOL><DEDENT>organisation = slugify(organisation)<EOL>self._validate_organisation(organisation)<EOL>self.organisation = organisation<EOL>return self<EOL>
Add an organisation segment.

        Args:
            organisation (str): Official name of an administrative body
                holding an election.

        Returns:
            IdBuilder

        Raises:
            ValueError