Adds a contact person to the description
        :type person: satosa.metadata_creation.description.ContactPersonDesc
        :param person: The contact person to be added

def add_contact_person(self, person):
        """
        Adds a contact person to the description
        :type person: satosa.metadata_creation.description.ContactPersonDesc
        :param person: The contact person to be added
        """
        if not isinstance(person, ContactPersonDesc):
            raise TypeError("person must be of type ContactPersonDesc")
        self._contact_person.append(person)