def get_relationships_for_source(self, source_id=None):
if source_id is None:<EOL><INDENT>raise NullArgument()<EOL><DEDENT>url_path = ('<STR_LIT>' +<EOL>self._catalog_idstr + '<STR_LIT>' +<EOL>str(source_id))<EOL>return objects.RelationshipList(self._get_request(url_path))<EOL>
Gets a ``RelationshipList`` corresponding to the given peer ``Id``.

        arg:    source_id (osid.id.Id): a peer ``Id``
        return: (osid.relationship.RelationshipList) - the relationships
        raise:  NullArgument - ``source_id`` is ``null``
        raise:  OperationFailed - unable to complete request
        raise:  PermissionDenied - authorization failure
        *compliance: mandatory -- This method must be implemented.*