def get_relationship_family_assignment_session(self):
if not self.supports_relationship_family_assignment():<EOL><INDENT>raise Unimplemented()<EOL><DEDENT>try:<EOL><INDENT>from . import sessions<EOL><DEDENT>except ImportError:<EOL><INDENT>raise OperationFailed()<EOL><DEDENT>try:<EOL><INDENT>session = sessions.RelationshipFamilyAssignmentSession(proxy=self._proxy,<EOL>runtime=self._runtime)<EOL><DEDENT>except AttributeError:<EOL><INDENT>raise OperationFailed()<EOL><DEDENT>return session<EOL>
Gets the ``OsidSession`` associated with assigning relationships to families.

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