code: @Test public void testgetNames(){
    DefaultedHttpParams params=new DefaultedHttpParams(addParams("local"),addParams("default"));
    Set<String> nameSet=params.getNames();
    Assert.assertEquals(3,nameSet.size());
    Set<String> localnameSet=params.getLocalNames();
    Assert.assertEquals(2,localnameSet.size());
    Set<String> defaultnameSet=params.getDefaultNames();
    Assert.assertEquals(2,defaultnameSet.size());
    params.setParameter("new",null);
    Assert.assertEquals(3,nameSet.size());
    Assert.assertEquals(2,localnameSet.size());
    Assert.assertEquals(2,defaultnameSet.size());
    nameSet=params.getNames();
    localnameSet=params.getLocalNames();
    defaultnameSet=params.getDefaultNames();
    Assert.assertEquals(4,nameSet.size());
    Assert.assertEquals(3,localnameSet.size());
    Assert.assertEquals(2,defaultnameSet.size());
  }
  