    @Test
    public void testGetLinearUnit() {

        PJDatum pj;
        pj = new PJDatum(null, "+proj=merc +to_meter=" + (1 + PJDatum.EPS/2));
        assertSame(Units.METRE, pj.getLinearUnit(false));
        pj = new PJDatum(null, "+proj=merc +to_meter=" + (1000 - PJDatum.EPS/2));
        assertSame(Units.KILOMETRE, pj.getLinearUnit(false));
    }