{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[13] *}

Let's focus on the parameters declared:

* Even though this function is a dependency ("dependable") itself, it also declares another dependency (it "depends" on something else).
    * It depends on the `query_extractor`, and assigns the value returned by it to the parameter `q`.
* It also declares an optional `last_query` cookie, as a `str`.

    /** Offset to the parameters in secondary requests */
    protected int secondaryParameterOffset;
    /** Number of parameter bytes being sent in this request */
    protected int parameterCount;
    /** Offset from the start of the SMB header to the parameter bytes */
    protected int parameterOffset;
    /** Displacement of these parameter bytes from the start of the total parameter block */

import java.lang.annotation.Target;

/**
 * Marks a method as an event subscriber.
 *
 * <p>The type of event will be indicated by the method's first (and only) parameter, which cannot
 * be primitive. If this annotation is applied to methods with zero parameters, or more than one
 * parameter, the object containing the method will not be able to register for event delivery from
 * the {@link EventBus}.
 *

 *      </td>
 *   </tr>
 *   <tr>
 *      <td>parameters</td>
 *      <td>N/A</td>
 *      <td>No</td>
 *      <td>Specifications for the parameters which this Mojo uses will be provided in <b>parameter</b> sub-elements
 *          in this section.
 *          <br>
 *          <i>NOTE: Parameters are discussed in more detail below.</i>
 *      </td>
 *   </tr>
 * </table>

Aber dieser Leitfaden zeigt Ihnen mehr oder weniger, wie die beiden normalerweise verwendet werden.

///

### Pydantics `exclude_unset`-Parameter verwenden { #using-pydantics-exclude-unset-parameter }

Wenn Sie Teil-Aktualisierungen entgegennehmen, ist der `exclude_unset`-Parameter in der `.model_dump()`-Methode von Pydantic-Modellen sehr nützlich.

Wie in `item.model_dump(exclude_unset=True)`.

   *
   * @param iterator the iterator whose minimum element is to be determined
   * @throws NoSuchElementException if {@code iterator} is empty
   * @throws ClassCastException if the parameters are not <i>mutually comparable</i> under this
   *     ordering.
   * @since 11.0
   */
  @ParametricNullness
  public <E extends T> E min(Iterator<E> iterator) {

In this case, this `__call__` is what **FastAPI** will use to check for additional parameters and sub-dependencies, and this is what will be called to pass a value to the parameter in your *path operation function* later.

## Parameterize the instance { #parameterize-the-instance }

And now, we can use `__init__` to declare the parameters of the instance that we can use to "parameterize" the dependency:

Puedes declarar múltiples parámetros de path y de query al mismo tiempo, **FastAPI** sabe cuál es cuál.

Y no tienes que declararlos en un orden específico.

Serán detectados por nombre:

{* ../../docs_src/query_params/tutorial004_py310.py hl[6,8] *}

## Parámetros de query requeridos { #required-query-parameters }

Wenn Sie **FastAPI** ein „Callable“ als Abhängigkeit übergeben, analysiert es die Parameter dieses „Callables“ und verarbeitet sie auf die gleiche Weise wie die Parameter einer *Pfadoperation-Funktion*. Einschließlich Unterabhängigkeiten.

Das gilt auch für Callables ohne Parameter. So wie es auch für *Pfadoperation-Funktionen* ohne Parameter gilt.

    @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,