def remove_child_families(self, family_id=None):
pass<EOL>
Removes all children from a family.

        arg:    family_id (osid.id.Id): the ``Id`` of a family
        raise:  NotFound - ``family_id`` not in hierarchy
        raise:  NullArgument - ``family_id`` is ``null``
        raise:  OperationFailed - unable to complete request
        raise:  PermissionDenied - authorization failure
        *compliance: mandatory -- This method must be implemented.*