fun duplexWithAuthChallenge() {
    enableProtocol(Protocol.HTTP_2)
    val credential = basic("jesse", "secret")
    client =
      client.newBuilder()
        .authenticator(RecordingOkAuthenticator(credential, null))
        .build()
    val body1 =
      MockStreamHandler()
        .sendResponse("please authenticate!\n")
        .requestIOException()
        .exhaustResponse()
    server.enqueue(

      init {
        val trustManager = trustManagerForCertificates(trustedCertificatesInputStream())
        val sslContext = SSLContext.getInstance("TLS")
        sslContext.init(null, arrayOf<TrustManager>(trustManager), null)
        val sslSocketFactory = sslContext.socketFactory

        client = OkHttpClient.Builder()
            .sslSocketFactory(sslSocketFactory, trustManager)
            .build()
      }

                messages.addErrorsBlankPassword("password");
            }, validationErrorLambda);
        }
        if (form.password != null && !form.password.equals(form.confirmPassword)) {
            form.confirmPassword = null;
            throwValidationError(messages -> {
                messages.addErrorsInvalidConfirmPassword("confirmPassword");
            }, validationErrorLambda);
        }

      return if (!fieldType.isInstance(value)) null else fieldType.cast(value)
    } catch (_: NoSuchFieldException) {
    }

    c = c.superclass
  }

  // Didn't find the field we wanted. As a last gasp attempt,
  // try to find the value on a delegate.
  if (fieldName != "delegate") {
    val delegate = readFieldOrNull(instance, Any::class.java, "delegate")

<div class="screenshot">
<img src="/img/tutorial/separate-openapi-schemas/image02.png">
</div>

Das bedeutet, dass es **immer einen Wert** hat, der Wert kann jedoch manchmal `None` sein (oder `null` in JSON).

        return System.getProperty(TEST_TOKEN, DEFAULT_TEST_TOKEN);
    }

    public static String settingTestToken() {
        final String testToken = System.getProperty(TEST_TOKEN);
        if (testToken != null) {
            logger.info("Token: {}", testToken);
            return testToken;
        }

        given().contentType("application/json").body("{\"index\":{\"_index\":\"fess_config.access_token\",\"_id\":\""

            url.scheme,
            challenge.realm,
            challenge.scheme,
            url.toUrl(),
            Authenticator.RequestorType.SERVER,
          )
        }

      if (auth != null) {
        val credentialHeader = if (proxyAuthorization) "Proxy-Authorization" else "Authorization"
        val credential =
          Credentials.basic(
            auth.userName,
            String(auth.password),

import java.util.AbstractMap.SimpleImmutableEntry;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A notification of the removal of a single entry. The key and/or value may be null if they were
 * already garbage collected.
 *
 * <p>Like other {@code Entry} instances associated with {@code CacheBuilder}, this class holds

 * support even a "normal" `TypeParameter<T>` when `<T>` has a nullable bound. (See the discussion
 * on TypeToken.where.) So, in the interest of failing fast and encouraging the user to switch to a
 * non-null bound if possible, let's require a non-null bound here.
 *
 * TODO(cpovirk): Elaborate on "wouldn't behave as users might expect."
 */
public abstract class TypeParameter<T> extends TypeCapture<T> {

  final TypeVariable<?> typeVariable;

  }

  @Override
  @CheckForNull
  public N removeInEdge(E edge, boolean isSelfLoop) {
    if (!isSelfLoop) {
      return removeOutEdge(edge);
    }
    return null;
  }

  @Override
  public N removeOutEdge(E edge) {
    N previousNode = incidentEdgeMap.remove(edge);
    // We're relying on callers to call this method only with an edge that's in the graph.