* The returned client installs a default event listener that gathers debug information. This will
   * be logged if the test fails.
   *
   * This client is also configured to be slightly more deterministic, returning a single IP
   * address for all hosts, regardless of the actual number of IP addresses reported by DNS.
   */
  fun newClient(): OkHttpClient {
    var client = testClient
    if (client == null) {
      client =

    }

    public MetadataGraph(int nVertices, int nEdges) {
        init(nVertices, nEdges);
    }
    // ------------------------------------------------------------------------
    /**
     * construct a single vertex
     */
    public MetadataGraph(MetadataGraphVertex entry) throws MetadataResolutionException {
        checkVertex(entry);
        checkVertices(1);

        entry.setCompareVersion(versionedVertices);

        LEAST_CONNECTIONS,
        /** Random selection */
        RANDOM,
        /** Failover only (use primary until failure) */
        FAILOVER_ONLY
    }

    /**
     * Represents a group of channels for a single session.
     */
    public static class ChannelGroup {
        private final String sessionId;
        private final List<ChannelInfo> channels = new CopyOnWriteArrayList<>();

![ReDoc](https://fastapi.tiangolo.com/img/index/index-02-redoc-simple.png)

## Ein Docker-Image mit einem Single-File-FastAPI erstellen { #build-a-docker-image-with-a-single-file-fastapi }

Wenn Ihr FastAPI eine einzelne Datei ist, zum Beispiel `main.py` ohne ein `./app`-Verzeichnis, könnte Ihre Dateistruktur wie folgt aussehen:

```
.
├── Dockerfile

   *
   * <p>This test might fail in GWT because the GWT emulations might count on the input collection
   * not to change during the copy. It is safe to do so in GWT because javascript is
   * single-threaded.
   */
  @GwtIncompatible // GWT is single threaded
  public void testCopyOf_threadSafe() {
    /*
     * The actual collections that we pass as inputs will be wrappers around these, so

            }
        }

        @Override
        public void close() {
            this.executor.close();
        }

        /**
         * Processes a single build step, deciding whether to schedule it for execution or skip it.
         *
         * @param step The build step to process
         */
        private void processStep(BuildStep step) {

            context.info("directory: " + options.directory().get());
        }

        context.unindent();
        context.println();
    }

    /**
     * Logs the result of a single strategy execution.
     */
    private void logStrategyResult(UpgradeContext context, UpgradeStrategy strategy, UpgradeResult result) {
        if (!result.errorPoms().isEmpty()) {

`Body` hat die gleichen zusätzlichen Validierungs- und Metadaten-Parameter wie `Query`, `Path` und andere, die Sie später kennenlernen werden.

///

## Einen einzelnen Body-Parameter einbetten { #embed-a-single-body-parameter }

Nehmen wir an, Sie haben nur einen einzelnen `item`-Body-Parameter von einem Pydantic-Modell `Item`.

Standardmäßig wird **FastAPI** dann seinen Body direkt erwarten.

      transitionStates.add(state());
      return directExecutor();
    }
  }

  // Functional tests using real thread. We only verify publicly visible state.
  // Interaction assertions are done by the single-threaded unit tests.

  private static class DefaultService extends AbstractIdleService {
    @Override
    protected void startUp() throws Exception {}

    @Override

   */
  /*
   * TODO(cpovirk): Is the unchecked cast avoidable? Would System.arraycopy be similarly fast (if
   * likewise not type-checked)? Could our single caller do something different?
   */
  @SuppressWarnings({"nullness", "unchecked"})
  static <T extends @Nullable Object> T[] copy(Object[] source, int from, int to, T[] arrayOfType) {