if RelationMember.find(:first, :joins => "INNER JOIN current_relations ON current_relations.id=current_relation_members.id",
:conditions => [ "visible = 1 AND member_type='way' and member_id=?", self.id])
raise OSM::APIPreconditionFailedError
if RelationMember.find(:first, :joins => "INNER JOIN current_relations ON current_relations.id=current_relation_members.id",
:conditions => [ "visible = 1 AND member_type='way' and member_id=?", self.id])
raise OSM::APIPreconditionFailedError