@Test
public void testFilterDictionary() throws Exception {

  final Hashtable<String, String> h = new Hashtable<>();
  h.put("w.p.key1", "1");
  h.put("x", "2");
  h.put("w.p.key2", "2");
  h.put("y", "2");
  final Map<String, String> f = OsgiUtil.filterByPrefix(h, "w.p.");
  assertEquals(2, f.size());
  assertEquals("1", f.get("key1"));
  assertEquals("2", f.get("key2"));
}