anchor.diff:  then([i, upgrade, the, connection, with, a, websocket, handshake], _State, _) ->
     receive
       {client_headers, Headers} ->
  -      io:format("H ~w ~n", [Headers])
  +      ok
     end,
  -  false.
  +  assert_that("Upgrade", is(get_header("connection", Headers))).
   
   %
   % Mock a http server
  
positive.code:       Headers = headers(Rest, []),
        %io:format("Hewders ~w ~n", [_Headers]),
        Tester ! {client_headers, Headers},
        _SecWebSocketKey = 'Sec-WebSocket-Key'(Rest),
        HandShake = [
          "HTTP/1.1 101 Web Socket Protocol Handshake\r\n",
          "Upgrade: WebSocket\r\n",
  
negative.code:       Acc
    end.
  
  wait(_Socket)->
    false.
  
  get_header(Key, Headers) ->
    proplists:get_value(Key, Headers).
  