listenerStatus:        lds,
				routeStatus:           rds,
				endpointStatus:        eds,
				extensionconfigStatus: ecds,
			})
			if len(fullStatus) == 0 {
				return nil, nil, fmt.Errorf("no proxies found (checked %d istiods)", len(drs))
			}

			sort.Slice(fullStatus, func(i, j int) bool {
				return fullStatus[i].proxyID < fullStatus[j].proxyID
			})
		}
	}
	if len(mappedResp) > 0 {

 * connection the client has many options:
 *
 *  * **HTTP proxy:** a proxy server may be explicitly configured for the client. Otherwise, the
 *    [proxy selector][java.net.ProxySelector] is used. It may return multiple proxies to attempt.
 *  * **IP address:** whether connecting directly to an origin server or a proxy, opening a socket
 *    requires an IP address. The DNS server may return multiple IP addresses to attempt.
 *

//// tab | Python 3.8+

```Python hl_lines="10"
{!> ../../docs_src/header_params/tutorial002.py!}
```

////

/// warning | "Aviso"

Antes de definir `convert_underscores` como `False`, lembre-se de que alguns proxies e servidores HTTP não permitem o uso de cabeçalhos com sublinhados.

///

## Cabeçalhos duplicados

É possível receber cabeçalhos duplicados. Isso significa, o mesmo cabeçalho com vários valores.

    }

    @Override public void proxySelectStart(Call call, HttpUrl url) {
      printEvent("proxySelectStart");
    }

    @Override public void proxySelectEnd(Call call, HttpUrl url, List<Proxy> proxies) {
      printEvent("proxySelectEnd");
    }

    @Override public void dnsStart(Call call, String domainName) {
      printEvent("dnsStart");
    }

     * @return requested (de-)activation(s) of profile(s) in this execution. Never {@code null}.
     */
    ProfileActivation getProfileActivation();

    // Proxies
    List<Proxy> getProxies();

    MavenExecutionRequest setProxies(List<Proxy> proxies);

    MavenExecutionRequest addProxy(Proxy proxy);

    // Servers
    List<Server> getServers();

///

```Python hl_lines="10"
{!> ../../docs_src/header_params/tutorial002.py!}
```

////

/// warning

Before setting `convert_underscores` to `False`, bear in mind that some HTTP proxies and servers disallow the usage of headers with underscores.

///

## Duplicate headers

It is possible to receive duplicate headers. That means, the same header with multiple values.

    override val call: Call,
    val url: HttpUrl,
  ) : CallEvent()

  data class ProxySelectEnd(
    override val timestampNs: Long,
    override val call: Call,
    val url: HttpUrl,
    val proxies: List<Proxy>?,
  ) : CallEvent() {
    override fun closes(event: CallEvent): Boolean = event is ProxySelectStart && call == event.call && url == event.url
  }

  data class DnsStart(
    override val timestampNs: Long,

    }

    @Override public void proxySelectStart(Call call, HttpUrl url) {
      printEvent("proxySelectStart");
    }

    @Override public void proxySelectEnd(Call call, HttpUrl url, List<Proxy> proxies) {
      printEvent("proxySelectEnd");
    }

    @Override public void callStart(Call call) {
      printEvent("callStart");
    }

    @Override public void dnsStart(Call call, String domainName) {

  protocols: List<Protocol>,
  connectionSpecs: List<ConnectionSpec>,
  /**
   * Returns this address's proxy selector. Only used if the proxy is null. If none of this
   * selector's proxies are reachable, a direct connection will be attempted.
   */
  @get:JvmName("proxySelector") val proxySelector: ProxySelector,
) {
  /**

// Returns a hexadecimal representation of time at the
// time response is sent to the client.
func mustGetRequestID(t time.Time) string {
	return fmt.Sprintf("%X", t.UnixNano())
}

// setEventStreamHeaders to allow proxies to avoid buffering proxy responses
func setEventStreamHeaders(w http.ResponseWriter) {
	w.Header().Set(xhttp.ContentType, "text/event-stream")
	w.Header().Set(xhttp.CacheControl, "no-cache") // nginx to turn off buffering