@Test
public void mergeEmptyThemeSingleSubtheme() {

    final Theme subTheme = createTheme( "Subtheme", -180.0, -90.0, 180.0, 90, null, null, null );
    final List<Theme> subThemes = singletonList( subTheme );
    final Theme theme = createThemeWithoutMetadata( "Theme", null, subThemes );
    final LayerMetadata merged = merger.merge( theme );
    assertEquals( "Theme", merged.getName() );
    final Description description = merged.getDescription();
    assertEquals( 0, description.getTitles().size() );
    assertEquals( 0, description.getAbstracts().size() );
    assertEquals( 0, description.getKeywords().size() );
    assertNull( merged.getSpatialMetadata() );
}