newOnce.Do(startNewServer)
	testRPC(t, newServerAddr)
	testNewServerRPC(t, newServerAddr)
}

func testRPC(t *testing.T, addr string) {
	client, err := Dial("tcp", addr)
	if err != nil {
		t.Fatal("dialing", err)
	}
	defer client.Close()

	// Synchronous calls
	args := &Args{7, 8}
	reply := new(Reply)
	err = client.Call("Arith.Add", args, reply)
	if err != nil {

	}

	const fallbackDelay = 100 * time.Millisecond

	var dialing sync.WaitGroup
	dialing.Add(2)
	origTestHookDialTCP := testHookDialTCP
	defer func() { testHookDialTCP = origTestHookDialTCP }()
	testHookDialTCP = func(ctx context.Context, net string, laddr, raddr *TCPAddr) (*TCPConn, error) {
		// Wait until Happy Eyeballs kicks in and both connections are dialing,
		// and inhibit cancellation.

				clientmetrics.Metrics.GetClientConnectionsMetric().WithLabelValues("dialing").Inc()
			},
			want: `
# HELP konnectivity_network_proxy_client_client_connections Number of open client connections, by status (Example: dialing)
# TYPE konnectivity_network_proxy_client_client_connections gauge
konnectivity_network_proxy_client_client_connections{status="dialing"} 1
`,
		},
	}
	for _, tc := range testcases {

	if use {
		*m = mptcpEnabled
	} else {
		*m = mptcpDisabled
	}
}

// A Dialer contains options for connecting to an address.
//
// The zero value for each field is equivalent to dialing
// without that option. Dialing with the zero value of Dialer
// is therefore equivalent to just calling the [Dial] function.
//
// It is safe to call Dialer's methods concurrently.
type Dialer struct {

			addr, proxyAddress, err)
	}
	if res.StatusCode != 200 {
		proxyConn.Close()
		return nil, fmt.Errorf("proxy error from %s while dialing %s, code %d: %v",
			proxyAddress, addr, res.StatusCode, res.Status)
	}

	// It's safe to discard the bufio.Reader here and return the
	// original TCP conn directly because we only use this for

	proxier func(req *http.Request) (*url.URL, error)

	// pingPeriod is a period for sending Ping frames over established
	// connections.
	pingPeriod time.Duration

	// upgradeTransport is an optional substitute for dialing if present. This field is
	// mutually exclusive with the "tlsConfig", "Dialer", and "proxier".
	upgradeTransport http.RoundTripper
}

var _ utilnet.TLSClientConfigHolder = &SpdyRoundTripper{}

func localPipe(t testing.TB) (net.Conn, net.Conn) {
	localListener.mu.Lock()
	defer localListener.mu.Unlock()

	addr := localListener.addr

	var err error
Dialing:
	// We expect a rare mismatch, but probably not 5 in a row.
	for i := 0; i < 5; i++ {
		tooSlow := time.NewTimer(1 * time.Second)
		defer tooSlow.Stop()
		var c1 net.Conn

	if h.UseLocationHost {
		clone.Host = h.Location.Host
	}
	clone.URL = &location
	klog.V(6).Infof("UpgradeAwareProxy: dialing for SPDY upgrade with headers: %v", clone.Header)
	backendConn, err = h.DialForUpgrade(clone)
	if err != nil {
		klog.V(6).Infof("Proxy connection error: %v", err)
		h.Responder.Error(w, req, err)
		return true
	}

				}
				theSocket := tmpFile.Name()
				os.Remove(theSocket)
				tmpFile.Close()

				con, err := net.Listen("unix", theSocket)
				if err != nil {
					t.Fatalf("unexpected error while dialing a socket: %v", err)
				}
				defer con.Close()

				if !isExistingSocket("unix://" + theSocket) {
					t.Fatalf("isExistingSocket(%q) gave unexpected result. Should have been true, instead of false", theSocket)

	// maintains a pool of idle connections for efficient re-use.
	//
	// The provided context.Context is for dialing purposes only
	// (see net.DialContext) and should not be stored or used for
	// other purposes. A default timeout should still be used
	// when dialing as a connection pool may call Connect
	// asynchronously to any query.
	//
	// The returned connection is only used by one goroutine at a