def unassign_relationship_from_family(self, relationship_id=None, family_id=None):
pass<EOL>
Removes a ``Relationship`` from a ``Family``.

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