code: @Test public void testSinglePadding(){
    TwoWayKey2StringMapper mapper=new IndexedKeyFormatMapper(createPersistenceList(16));
    Assert.assertTrue(mapper.isSupportedType(Type.TYPE00.getClass()));
    Assert.assertTrue(mapper.isSupportedType(Type.TYPE15.getClass()));
    Assert.assertFalse(mapper.isSupportedType(Type.TYPE16.getClass()));
    Assert.assertFalse(mapper.isSupportedType(Type.TYPE17.getClass()));
    String result=mapper.getStringMapping(Type.TYPE00);
    Assert.assertSame(Type.TYPE00,mapper.getKeyMapping(result));
    Assert.assertEquals("0TYPE00",result);
    result=mapper.getStringMapping(Type.TYPE15);
    Assert.assertSame(Type.TYPE15,mapper.getKeyMapping(result));
    Assert.assertEquals("FTYPE15",result);
  }
  