And when solving the dependency, **FastAPI** will call this `checker` like:

```Python
checker(q="somequery")
```

...and pass whatever that returns as the value of the dependency in our *path operation function* as the parameter `fixed_content_included`:

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[22] *}

/// tip

All this might seem contrived. And it might not be very clear how is it useful yet.

   * {@code factory}, and the multimap contents are all serializable.
   *
   * <p>The multimap is not threadsafe when any concurrent operations update the multimap, even if
   * {@code map} and the instances generated by {@code factory} are. Concurrent read operations will
   * work correctly. To allow concurrent update operations, wrap the multimap with a call to {@link
   * #synchronizedMultimap}.
   *

        @Override
        public void call(Listener listener) {
          listener.starting();
        }

        @Override
        public String toString() {
          return "starting()";
        }
      };
  private static final ListenerCallQueue.Event<Listener> RUNNING_EVENT =
      new ListenerCallQueue.Event<Listener>() {
        @Override
        public void call(Listener listener) {
          listener.running();

    private final Callable<T> delegate;

    WrappedCallable(Callable<T> delegate) {
      this.delegate = delegate;
    }

    @Override
    public T call() throws Exception {
      return delegate.call();
    }
  }

  private static final class WrappedRunnable implements Runnable {
    private final Runnable delegate;

    WrappedRunnable(Runnable delegate) {

    .sslSocketFactory(clientCertificates.sslSocketFactory(), clientCertificates.trustManager())
    .build();

// Connect 'em all together. Certificates are exchanged in the handshake.
Call call = client.newCall(new Request.Builder()
    .url(server.url("/"))
    .build());
Response response = call.execute();
System.out.println(response.handshake().peerPrincipal());
RecordedRequest recordedRequest = server.takeRequest();

  }

  /**
   * Verifies that a collection is immutable.
   *
   * <p>A collection is considered immutable if:
   *
   * <ol>
   *   <li>All its mutation methods result in UnsupportedOperationException, and do not change the
   *       underlying contents.
   *   <li>All methods that return objects that can indirectly mutate the collection throw
   *       UnsupportedOperationException when those mutators are called.
   * </ol>

        }
    }

    @Nested
    @DisplayName("Mockito interactions")
    class MockitoInteractions {

        @Mock
        SSPContext mockCtx;

        // Helper exercising all SSPContext methods to verify call interactions.
        private void useContext(SSPContext ctx) throws Exception {
            ctx.getSigningKey();
            ctx.isEstablished();
            ctx.initSecContext(new byte[] { 1, 2, 3 }, 1, 1);

        testDir = testFile.getParentFile(); // the testdata directory
      } catch (Exception ignore) {
        // probably URISyntaxException or IllegalArgumentException
        // fall back to copying URLs to files in the testDir == null block below
      }
    }

    if (testDir == null) {
      // testdata resources aren't file:// urls, so create a directory to store them in and then

Jetzt springen wir zu den spannenden Dingen. 🎉

## `Query` zu `Annotated` im `q`-Parameter hinzufügen { #add-query-to-annotated-in-the-q-parameter }

Da wir nun `Annotated` haben, in das wir mehr Informationen (in diesem Fall einige zusätzliche Validierungen) einfügen können, fügen Sie `Query` innerhalb von `Annotated` hinzu und setzen Sie den Parameter `max_length` auf `50`:

{* ../../docs_src/query_params_str_validations/tutorial002_an_py310.py hl[9] *}

    while (lines.peek() == null) {
      Java8Compatibility.clear(cbuf);
      // The default implementation of Reader#read(CharBuffer) allocates a
      // temporary char[], so we call Reader#read(char[], int, int) instead.
      int read = (reader != null) ? reader.read(buf, 0, buf.length) : readable.read(cbuf);
      if (read == -1) {
        lineBuf.finish();
        break;
      }