@utilities.remove_null_proxy_kwarg<EOL><INDENT>def get_family_hierarchy_design_session(self):<DEDENT>
if not self.supports_family_hierarchy_design():<EOL><INDENT>raise errors.Unimplemented()<EOL><DEDENT>return sessions.FamilyHierarchyDesignSession(runtime=self._runtime)<EOL>
Gets the ``OsidSession`` associated with the family hierarchy design service.

        return: (osid.relationship.FamilyHierarchyDesignSession) - a
                ``HierarchyDesignSession`` for families
        raise:  OperationFailed - unable to complete request
        raise:  Unimplemented - ``supports_family_hierarchy_design()``
                is ``false``
        *compliance: optional -- This method must be implemented if
        ``supports_family_hierarchy_design()`` is ``true``.*