Labor leaders don't like it when they have to open their books to public inspection. Those in Canada apparently aren't much different from the ones in this country. Canadian lawmakers currently are considering private legislation, Public Financial Disclosure for Labour Organizations, to include unions as among the organizations required to furnish financial data. Sponsors say the measure, alternately known as C-377, is needed to combat corruption and foster transparency. Union leaders insist that compliance would be unjustifiably costly and time-consuming. If this sounds familiar, it should.