If for some reason you need to disable automatic conversion of underscores to hyphens, set the parameter `convert_underscores` of `Header` to `False`:

{* ../../docs_src/header_params/tutorial002_an_py310.py hl[10] *}

/// warning

Before setting `convert_underscores` to `False`, bear in mind that some HTTP proxies and servers disallow the usage of headers with underscores.

///

## Réponse supplémentaire avec `model`

Vous pouvez ajouter à votre décorateur de *paramètre de chemin* un paramètre `responses`.

Il prend comme valeur un `dict` dont les clés sont des codes HTTP pour chaque réponse, comme `200`, et la valeur de ces clés sont d'autres `dict` avec des informations pour chacun d'eux.

Chacun de ces `dict` de réponse peut avoir une clé `model`, contenant un modèle Pydantic, tout comme `response_model`.

fix. Even if you think it's relatively minor, it's helpful to know what people
are working on. And as mentioned above, API changes should be discussed
thoroughly before moving to code.

Some examples of types of pull requests that are immediately helpful:

  - Fixing a bug without changing a public API.
  - Fixing or improving documentation.
  - Improvements to Maven configuration.

## HTTPX { #httpx }

Even if your **FastAPI** application uses normal `def` functions instead of `async def`, it is still an `async` application underneath.

            if (queryBuilder != null) {
                builder.setQuery(queryBuilder);
            }
            _conditionQuery.getFieldSortBuilderList().forEach(sort -> {
                builder.addSort(sort);
            });
        }

        if (_conditionAggregation != null) {
            _conditionAggregation.getAggregationBuilderList().forEach(builder::addAggregation);
        }

import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import org.jspecify.annotations.NullMarked;

/**
 * An {@link ClusterException} is a data structure that allows for some code to "throw multiple
 * exceptions", or something close to it. The prototypical code that calls for this class is
 * presented below:
 *
 * <pre>
 * void runManyThings({@literal List<ThingToRun>} thingsToRun) {

     * is given by {@link #getSource()}.
     *
     * @return The one-based index of the line containing the problem or a non-positive value if unknown.
     */
    int getLineNumber();

    /**
     * Gets the one-based index of the column containing the problem. The column number should refer to some text file
     * that is given by {@link #getSource()}.
     *

The **Advanced User Guide** builds on this one, uses the same concepts, and teaches you some extra features.

But you should first read the **Tutorial - User Guide** (what you are reading right now).

## Forbid Extra Query Parameters { #forbid-extra-query-parameters }

In some special use cases (probably not very common), you might want to **restrict** the query parameters that you want to receive.

You can use Pydantic's model configuration to `forbid` any `extra` fields:

{* ../../docs_src/query_param_models/tutorial002_an_py310.py hl[10] *}

     *
     * <p>This method performs a paginated search through all duplicate host configurations,
     * applying any search filters specified in the pager. The results are sorted
     * by sort order, creation time, regular name, and duplicate hostname.</p>
     *
     * @param duplicateHostPager the pager containing search criteria and pagination settings