<img src="/img/tutorial/sub-applications/image02.png">

If you try interacting with any of the two user interfaces, they will work correctly, because the browser will be able to talk to each specific app or sub-app.

### Technical Details: `root_path`

// about HTTP headers, Set should be used instead of
// http.Header.Set(...). Otherwise, some S3 clients will not
// able to extract the ETag.
func Set(etag ETag, h http.Header) {
	// Some (broken) S3 clients expect the ETag header to
	// literally "ETag" - not "Etag". Further, some clients
	// expect an ETag in double quotes. Therefore, we set the
	// ETag directly as map entry instead of using http.Header.Set

            return optList;
        }
    }

    String getOptionsAsHtml() {
        StringBuilder sb = new StringBuilder(512);
        boolean odd = true;
        sb.append(
                "<table border='1' class='zebra-striped'><tr class='a'><th><b>Options</b></th><th><b>Description</b></th></tr>");
        for (Option option : new CLIManagerExtension().getOptions()) {
            odd = !odd;
            sb.append("<tr class='");

hinzugefügt werden können. <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">Verwenden Sie dafür das Präfix 'X-'</a>.

Wenn Sie jedoch benutzerdefinierte Header haben, die ein Client in einem Browser sehen soll, müssen Sie sie zu Ihrer CORS-Konfigurationen ([CORS (Cross-Origin Resource Sharing)](cors.md){.internal-link target=_blank}) hinzufügen, indem Sie den Parameter `expose_headers` verwenden, der in der <a href="https://www.starlette.io/...

    throw new UnsupportedOperationException();
  }

  /**
   * Not supported. <b>You are attempting to create a set that may contain a non-{@code Comparable}
   * element.</b> Proper calls will resolve to the version in {@code ImmutableSortedSet}, not this
   * dummy version.
   *
   * @throws UnsupportedOperationException always

Header <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">mittels des Präfix 'X-'</a> hinzugefügt werden können.

Wenn Sie jedoch benutzerdefinierte Header haben, die ein Client in einem Browser sehen können soll, müssen Sie diese zu Ihren CORS-Konfigurationen hinzufügen (weitere Informationen finden Sie unter [CORS (Cross-Origin Resource Sharing)](../tutorial/cors.md){.internal-link target=_blank}), unter Verwendung des Parameters `expose_headers`,...

that custom proprietary headers can be added <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">using the 'X-' prefix</a>.

But if you have custom headers that you want a client in a browser to be able to see, you need to add them to your CORS configurations (read more in [CORS (Cross-Origin Resource Sharing)](../tutorial/cors.md){.internal-link target=_blank}), using the parameter `expose_headers` documented in <a href="https://www....

  private var failFastResponse: MockResponse? = null

  @Throws(InterruptedException::class)
  override fun dispatch(request: RecordedRequest): MockResponse {
    // To permit interactive/browser testing, ignore requests for favicons.
    val requestLine = request.requestLine
    if (requestLine == "GET /favicon.ico HTTP/1.1") {
      logger.info("served $requestLine")

Então, vamos rever de um ponto de vista simplificado:

* O usuário digita o `username` e a `senha` no frontend e aperta `Enter`.
* O frontend (rodando no browser do usuário) manda o `username` e a `senha` para uma URL específica na sua API (declarada com `tokenUrl="token"`).
* A API checa aquele `username` e `senha`, e responde com um "token" (nós não implementamos nada disso ainda).

import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import junit.framework.TestCase;

/**
 * Unit tests for {@link Closeables}.
 *
 * <p>Checks proper closing behavior, and ensures that IOExceptions on Closeable.close() are not
 * propagated out from the {@link Closeables#close} method if {@code swallowException} is true.
 *
 * @author Michael Lancaster
 */