AssetGroup { public String getExtension() { return _type != null ? _type.getExtension() : null; }  String getName(); void setName(String name); String getUrl(); void setUrl(String url); AssetType getType(); void setType(AssetType type); void addAsset(Asset asset); List<Asset> getAssets(); String getExtension(); @Override String toString();  }
@Test public void testGetExtension() throws Exception { AssetGroup cssGroup = new AssetGroup(); assertEquals(null, cssGroup.getExtension()); cssGroup.setType(AssetType.CSS); assertEquals("css", cssGroup.getExtension()); }