{* ../../docs_src/behind_a_proxy/tutorial004_py39.py hl[9] *}

and then it won't include it in the OpenAPI schema.

## Mounting a sub-application { #mounting-a-sub-application }

If you need to mount a sub-application (as described in [Sub Applications - Mounts](sub-applications.md){.internal-link target=_blank}) while also using a proxy with `root_path`, you can do it normally, as you would expect.

It might be useful, for example, to return custom headers or cookies.

## Return a `Response` { #return-a-response }

In fact, you can return any `Response` or any sub-class of it.

/// tip

`JSONResponse` itself is a sub-class of `Response`.

///

And when you return a `Response`, **FastAPI** will pass it directly.

                return true;
            }

            id = project.getGroupId() + id;

            return id.equals(selector);
        }

        // relative path, e.g. "sub", "../sub" or "."
        else if (reactorDirectory != null) {
            File selectedProject =
                    new File(new File(reactorDirectory, selector).toURI().normalize());

package org.gradle.test.sub;

public interface SubJavaInterface {

    def iter_data():
        yield json.dumps(
            {"func_is_open": function_session.open, "req_is_open": request_session.open}
        )

    return StreamingResponse(iter_data())


@app.get("/sub")
def get_sub(sessions: NamedSessionsDep) -> Any:
    def iter_data():
        yield json.dumps(
            {"named_session_open": sessions[0].open, "session_open": sessions[1].open}
        )

	if p := handlerPrefixes[h]; p != "" {
		prefix = p
	}
	trace := madmin.TraceInfo{
		TraceType: t.TraceType,
		FuncName:  prefix + "." + h.String(),
		NodeName:  remote,
		Time:      start,
		Duration:  end.Sub(start),
		Path:      t.Subroute,
		Error:     errString,
		Bytes:     int64(len(req) + len(resp)),
		HTTP: &madmin.TraceHTTPStats{
			ReqInfo: madmin.TraceRequestInfo{
				Time:    start,
				Proto:   "grid",

package org.gradle.test;

import org.gradle.test.sub.*;
import org.gradle.test.sub2.Sub2Interface;

import java.io.Closeable;
import java.io.IOException;

public class JavaClassWithImports extends SubClass implements SubJavaInterface, Sub2Interface, Closeable {
    public void close() throws IOException {
    }

	// e.g. Forwarded: for=192.0.2.60;proto=https;by=203.0.113.43
	forwarded = http.CanonicalHeaderKey("Forwarded")
	// Allows for a sub-match of the first value after 'for=' to the next
	// comma, semi-colon or space. The match is case-insensitive.
	forRegex = regexp.MustCompile(`(?i)(?:for=)([^(;|,| )]+)(.*)`)
	// Allows for a sub-match for the first instance of scheme (http|https)
	// prefixed by 'proto='. The match is case-insensitive.

Let's create a dependency `get_current_user`.

Remember that dependencies can have sub-dependencies?

`get_current_user` will have a dependency with the same `oauth2_scheme` we created before.

The same as we were doing before in the *path operation* directly, our new dependency `get_current_user` will receive a `token` as a `str` from the sub-dependency `oauth2_scheme`:

{* ../../docs_src/security/tutorial002_an_py310.py hl[25] *}

Vamos a crear una dependencia `get_current_user`.

¿Recuerdas que las dependencias pueden tener sub-dependencias?

`get_current_user` tendrá una dependencia con el mismo `oauth2_scheme` que creamos antes.

De la misma manera que estábamos haciendo antes en la *path operation* directamente, nuestra nueva dependencia `get_current_user` recibirá un `token` como un `str` de la sub-dependencia `oauth2_scheme`:

{* ../../docs_src/security/tutorial002_an_py310.py hl[25] *}