Set an organization to the description
        :type organization: satosa.metadata_creation.description.OrganizationDesc
        :param organization: Organization description

def organization(self, organization):
        """
        Set an organization to the description
        :type organization: satosa.metadata_creation.description.OrganizationDesc
        :param organization: Organization description
        """
        if not isinstance(organization, OrganizationDesc):
            raise TypeError("organization must be of type OrganizationDesc")
        self._organization = organization