{!> ../../../docs_src/body/tutorial004.py!}
    ```

The function parameters will be recognized as follows:

* If the parameter is also declared in the **path**, it will be used as a path parameter.
* If the parameter is of a **singular type** (like `int`, `float`, `str`, `bool`, etc) it will be interpreted as a **query** parameter.

        DEPRECATED_CORE_PARAMETERS = deprecatedCoreParameters;
    }

    @Inject
    DeprecatedCoreExpressionValidator(PluginValidationManager pluginValidationManager) {
        super(pluginValidationManager);
    }

    @Override
    protected String getParameterLogReason(Parameter parameter) {
        return "uses deprecated parameter expression '" + parameter.getDefaultValue() + "': "

        "paths": {
            "/": {
                "get": {
                    "summary": "Route With Extra Query Parameters",
                    "operationId": "route_with_extra_query_parameters__get",
                    "parameters": [
                        {
                            "required": False,
                            "schema": IsDict(
                                {

    @Suppress("UNCHECKED_CAST")
    fun generate(parameters: Map<String, Any>) {
        generateKotlinDslApiExtensionsSourceTo(
            parameters["asmLevel"] as Int,
            parameters["platformClassLoader"] as ClassLoader,
            parameters["incubatingAnnotationTypeDescriptor"] as String,
            parameters["outputDirectory"] as File,
            parameters["packageName"] as String,

# Body - Multiple Parameters

Now that we have seen how to use `Path` and `Query`, let's see more advanced uses of request body declarations.

## Mix `Path`, `Query` and body parameters

First, of course, you can mix `Path`, `Query` and request body parameter declarations freely and **FastAPI** will know what to do.

And you can also declare body parameters as optional, by setting the default to `None`:

=== "Python 3.10+"

    }
  }

  /*
   * Preconditions.checkNotNull is *intended* for performing eager null checks on parameters that a
   * nullness checker can already "prove" are non-null. That means that the first parameter to
   * checkNotNull *should* be annotated to require it to be non-null.
   *
   * However, for a variety of reasons, Google developers have written a ton of code over the past

    }

    public void test_convertParameterMap() {
        String parameters;
        Map<String, String> parameterMap;

        parameters = "";
        parameterMap = ParameterUtil.parse(parameters);
        assertEquals(0, parameterMap.size());

        parameters = "domain";
        parameterMap = ParameterUtil.parse(parameters);
        assertEquals(1, parameterMap.size());

  }

  public void testConstructor_parameters() throws Exception {
    Invokable<?, Prepender> delegate = Prepender.constructor(String.class, int.class);
    ImmutableList<Parameter> parameters = delegate.getParameters();
    assertEquals(2, parameters.size());
    assertEquals(String.class, parameters.get(0).getType().getType());
    assertTrue(parameters.get(0).isAnnotationPresent(NotBlank.class));

  fun emptyCache(parameters: Pair<FileSystem, Boolean>) {
    setUp(parameters.first, parameters.second)
    cache.close()
    assertJournalEquals()
  }

  @ParameterizedTest
  @ArgumentsSource(FileSystemParamProvider::class)
  fun recoverFromInitializationFailure(parameters: Pair<FileSystem, Boolean>) {
    setUp(parameters.first, parameters.second)

            Map<String, Object> parameters = new HashMap<>();
            // NOTE: These parameter names _must_ match the setter names in ReleaseNotesTransformer
            parameters.put("baseCss", getBaseCssFile().get().getAsFile());
            parameters.put("releaseNotesCss", getReleaseNotesCssFile().get().getAsFile());