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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def with_organisation(self, organisation):
 """Add an organisation segment. Args: organisation (str):
 Official name of an administrative body holding an election. Returns: IdBuilder Raises: ValueError """

        if organisation is None:
            organisation = ''
        organisation = slugify(organisation)
        self._validate_organisation(organisation)
        self.organisation = organisation
        return self