def delete_relationship(self, relationship_id=None):
if relationship_id is None:<EOL><INDENT>raise NullArgument()<EOL><DEDENT>if not isinstance(relationship_id, Id):<EOL><INDENT>raise InvalidArgument('<STR_LIT>')<EOL><DEDENT>url_path = ('<STR_LIT>' +<EOL>self._catalog_idstr + '<STR_LIT>' +<EOL>str(relationship_id))<EOL>result = self._delete_request(url_path)<EOL>return objects.Relationship(result)<EOL>
Deletes a ``Relationship``.

        arg:    relationship_id (osid.id.Id): the ``Id`` of the
                ``Relationship`` to remove
        raise:  NotFound - ``relationship_id`` not found
        raise:  NullArgument - ``relationship_id`` is ``null``
        raise:  OperationFailed - unable to complete request
        raise:  PermissionDenied - authorization failure
        *compliance: mandatory -- This method must be implemented.*