}
                /*
                 * Also look up an earlier node so that, if the graph is using MapRetrievalCache,
                 * we read one of the fields declared in that class.
                 */
                Set<Integer> unused = graph.successors(first);
                return null; // so the lambda is a Callable to propagate checked await() exceptions
              }));

```Python
q: Annotated[str | None, Query(min_length=3)] = None
```

So, when you need to declare a value as required while using `Query`, you can simply not declare a default value:

{* ../../docs_src/query_params_str_validations/tutorial006_an_py310.py hl[9] *}

### Required, can be `None` { #required-can-be-none }

      <artifactId>guava</artifactId>
      <version>${project.version}</version>
    </dependency>
    <!-- We redeclare the j2objc-annotations dependency from `guava`: Our Gradle
         Module Metadata hides the dependency declared in `guava` from runtime
         configurations downstream, and GWT uses the runtime configuration for
         its builds. Thus, GWT doesn't get j2objc-annotations transitively, in

            item_def["description"] = item_description
    # definitions: dict[DefsRef, dict[str, Any]]
    # but mypy complains about general str in other places that are not declared as
    # DefsRef, although DefsRef is just str:
    # DefsRef = NewType('DefsRef', str)
    # So, a cast to simplify the types here
    return field_mapping, cast(dict[str, dict[str, Any]], definitions)

     *       module path, but is also compatible with placement on the class path. Compatibility can
     *       be achieved, for example, by repeating in the {@code META-INF/services/} directory the services
     *       that are declared in the {@code module-info.class} file. In that case, the path type can be chosen
     *       by the plugin.</li>
     *   <li>If a {@link #patchModule(String)} is also set and the main JAR file is placed on the module path,

                }
                /*
                 * Also look up an earlier node so that, if the graph is using MapRetrievalCache,
                 * we read one of the fields declared in that class.
                 */
                Set<Integer> unused = graph.successors(first);
                return null; // so the lambda is a Callable to propagate checked await() exceptions
              }));

It will include all the routes from that router as part of it.

/// note | Technical Details

It will actually internally create a *path operation* for each *path operation* that was declared in the `APIRouter`.

So, behind the scenes, it will actually work as if everything was the same single app.

///

/// check

You don't have to worry about performance when including routers.

         * annotations in the form of JetBrains annotations, which have only class retention and
         * thus are invisible at runtime. Thus, we conclude that the parameter types are
         * *non*-nullable, even when they are declared as `Foo?`.
         */
        || hasAutomaticNullChecksFromKotlin(member);
  }

  private static boolean hasAutomaticNullChecksFromKotlin(Member member) {

        if (parameters.contains(parameter)) {
            throw new DuplicateParameterException(parameter.getName()
                    + " has been declared multiple times in mojo with goal: " + getGoal() + " (implementation: "
                    + getImplementation() + ")");
        }

        parameters.add(parameter);
    }

    /**

                            // and catch here rather than have it return null
                            if (rGroup == null) {
                                // relocated dependency artifact is declared excluded, no need to add and recurse
                                // further
                                continue;
                            }