@Test
void testTwoPackage() {

    assertEquals(
            Lists.newArrayList(
                    NameSpaceMappingBuilder.of("a.b",""),
                    NameSpaceMappingBuilder.of("a.c","")
            ),
            new TopLevelNameSpaceMapperCalculator().computeNameSpaceMapping(createDataSet("a.b.X", "a.c.Y", "a.c.Z"))
    );
}