code: @Test public void testSimple(){
    final HeaderMap headerMap=new HeaderMap();
    headerMap.add(Headers.HOST,"yay.undertow.io");
    assertEquals(1,headerMap.size());
    assertNotEquals(-1L,headerMap.fastIterate());
    assertEquals(-1L,headerMap.fiNext(headerMap.fastIterate()));
    assertEquals(Headers.HOST,headerMap.fiCurrent(headerMap.fastIterate()).getHeaderName());
    assertEquals("yay.undertow.io",headerMap.getFirst(Headers.HOST));
    assertEquals("yay.undertow.io",headerMap.getLast(Headers.HOST));
    assertEquals("yay.undertow.io",headerMap.get(Headers.HOST,0));
  }
  