### Preprocess the OpenAPI Specification for the Client Generator { #preprocess-the-openapi-specification-for-the-client-generator }

The generated code still has some **duplicated information**.

We already know that this method is related to the **items** because that word is in the `ItemsService` (taken from the tag), but we still have the tag name prefixed in the method name too. 😕

## 0.9.1

* Document receiving [Multiple values with the same query parameter](https://fastapi.tiangolo.com/tutorial/query-params-str-validations/#query-parameter-list-multiple-values) and [Duplicate headers](https://fastapi.tiangolo.com/tutorial/header-params/#duplicate-headers). PR [#95](https://github.com/tiangolo/fastapi/pull/95).

## 0.9.0

* Upgrade compatible Pydantic version to `0.21.0`. PR [#90](https://github.com/tiangolo/fastapi/pull/90).

Then we can declare `tags` as a set of strings:

{* ../../docs_src/body_nested_models/tutorial003_py310.py hl[12] *}

With this, even if you receive a request with duplicate data, it will be converted to a set of unique items.

And whenever you output that data, even if the source had duplicates, it will be output as a set of unique items.

And it will be annotated / documented accordingly too.

## Nested Models { #nested-models }

labels.pathmap_pt_both=Scansione/Visualizzazione
labels.pathmap_pt_stored=Conversione URL estratto
labels.regular_name=Nome regolare
labels.duplicate_name=Nome duplicato
labels.duplicate_host_configuration=Host duplicato
labels.duplicate_host_title_details=Host duplicato
labels.dashboard_title_configuration=Configurazione sistema
labels.dashboard_plugin=Plugin dashboard
labels.web_config_list=Elenco configurazioni web

    /** List of duplicate host rules for URL conversion */
    protected List<DuplicateHost> duplicateHostList;

    /**
     * Default constructor for DuplicateHostHelper.
     * Creates a new duplicate host helper instance.
     */
    public DuplicateHostHelper() {
        // Default constructor
    }

    /**
     * Initializes the duplicate host helper after construction.

):
    return [item, sub_item]


@app.post("/with-duplicates")
async def with_duplicates(item: Item, item2: Item = Depends(duplicate_dependency)):
    return [item, item2]


@app.post("/no-duplicates")
async def no_duplicates(item: Item, item2: Item = Depends(dependency)):
    return [item, item2]


@app.post("/with-duplicates-sub")
async def no_duplicates_sub(

labels.pathmap_pt_both=Crawling/Displaying
labels.pathmap_pt_stored=Extracted URL Conversion
labels.regular_name=Regular Name
labels.duplicate_name=Duplicate Name
labels.duplicate_host_configuration=Duplicate Host
labels.duplicate_host_title_details=Duplicate Host
labels.dashboard_title_configuration=System Config
labels.dashboard_plugin=Dashboard Plugin
labels.web_config_list=Web Config List

labels.pathmap_pt_both=Crawling/Displaying
labels.pathmap_pt_stored=Extracted URL Conversion
labels.regular_name=Regular Name
labels.duplicate_name=Duplicate Name
labels.duplicate_host_configuration=Duplicate Host
labels.duplicate_host_title_details=Duplicate Host
labels.dashboard_title_configuration=System Config
labels.dashboard_plugin=Dashboard Plugin
labels.web_config_list=Web Config List

        return fessConfig.getCrawlerDocumentMaxSymbolTermSizeAsInteger();
    }

    /**
     * Checks if duplicate term removal is enabled in configuration.
     *
     * @return true if duplicate terms should be removed, false otherwise
     */
    protected boolean isDuplicateTermRemoved() {
        final FessConfig fessConfig = ComponentUtil.getFessConfig();

/// warning | Advertencia

Antes de establecer `convert_underscores` a `False`, ten en cuenta que algunos proxies y servidores HTTP no permiten el uso de headers con guiones bajos.

///

## Headers duplicados { #duplicate-headers }

Es posible recibir headers duplicados. Eso significa, el mismo header con múltiples valores.

Puedes definir esos casos usando una lista en la declaración del tipo.