*
 * <p>This class is used only for micro-optimization. Standard {@code Future} utilities benefit from
 * this optimization, so there is no need to specialize methods to return or accept this type
 * instead of {@code ListenableFuture}.
 *
 * <p>This class is GWT-compatible.
 *

But remember that when you import `Query`, `Path`, `Header`, and others from `fastapi`, those are actually functions that return special classes.

///

/// info

To declare headers, you need to use `Header`, because otherwise the parameters would be interpreted as query parameters.

///

## Automatic conversion { #automatic-conversion }

need it so that empty directory does not get deleted...

    return string;
  }

  /**
   * Returns the escaped form of the given character, or {@code null} if this character does not
   * need to be escaped. If an empty array is returned, this effectively strips the input character
   * from the resulting text.
   *
   * <p>If the character does not need to be escaped, this method should return {@code null}, rather

And then you can set headers in that *temporal* response object.

{* ../../docs_src/response_headers/tutorial002_py310.py hl[1, 7:8] *}

And then you can return any object you need, as you normally would (a `dict`, a database model, etc).

And if you declared a `response_model`, it will still be used to filter and convert the object you returned.

The idea is that you would receive the payload and send it **directly** to an LLM provider, using a `prompt` to tell the LLM what to do, and return the response **as is**. No questions asked.

You don't even need to write the body of the function. The `@app.vibe()` decorator does everything for you based on AI vibes:

{* ../../docs_src/vibe/tutorial001_py310.py hl[8:12] *}

## Benefits { #benefits }

    Class<T> getType();

    /**
     * Creates a copy of the data suitable for storage in the cache. The original data to store can be mutated after the
     * cache is populated but the state of the cache must not change so we need to make a copy.
     *
     * @param data The data to store in the cache, must not be {@code null}.
     * @return The data being stored in the cache, never {@code null}.
     */
    T intoCache(T data);

    /**

# Extending OpenAPI { #extending-openapi }

There are some cases where you might need to modify the generated OpenAPI schema.

In this section you will see how.

## The normal process { #the-normal-process }

The normal (default) process, is as follows.

A `FastAPI` application (instance) has an `.openapi()` method that is expected to return the OpenAPI schema.

        // Directory leasing requires SMB 3.0 or higher
        // MS-SMB2: Level 2 leasing (which includes directory leasing) is only supported in SMB 3.0+
        // We'll validate this when we actually need to use the session

        // Request base lease
        Smb2LeaseKey leaseKey = baseLeaseManager.requestLease(directoryPath, requestedState);

        // Create directory cache entry

# JSON with Bytes as Base64 { #json-with-bytes-as-base64 }

If your app needs to receive and send JSON data, but you need to include binary data in it, you can encode it as base64.

## Base64 vs Files { #base64-vs-files }

Consider first if you can use [Request Files](../tutorial/request-files.md) for uploading binary data and [Custom Response - FileResponse](./custom-response.md#fileresponse--fileresponse-) for sending binary data, instead of encoding it in JSON.