code: @Test public void testCondensedHeader(){
    HeaderGroup headergroup=new HeaderGroup();
    Assert.assertNull(headergroup.getCondensedHeader("name"));
    Header header1=new BasicHeader("name","value1");
    Header header2=new BasicHeader("name","value2");
    Header header3=new BasicHeader("name","value3");
    headergroup.setHeaders(new Header[]{header1,header2,header3});
    Assert.assertEquals("value1, value2, value3",headergroup.getCondensedHeader("name").getValue());
    headergroup.setHeaders(new Header[]{header1});
    Assert.assertEquals(header1,headergroup.getCondensedHeader("name"));
  }
  