Now you can replace the `.openapi()` method with your new function.

{* ../../docs_src/extending_openapi/tutorial001_py39.py hl[29] *}

### Check it { #check-it }

Once you go to <a href="http://127.0.0.1:8000/redoc" class="external-link" target="_blank">http://127.0.0.1:8000/redoc</a> you will see that you are using your custom logo (in this example, **FastAPI**'s logo):

### GNU/Linux and macOS

```sh
docker-compose pull
docker-compose up
```

or

```sh

    else -> actualBranch
}

/**
 * The build environment.
 *
 * WARNING: Every val in here must not change for they same daemon. If it does, changes will go undetected,
 *          since this whole object is kept in the classloader between builds.
 *          Anything that changes must be in a val with a get() method that recomputes the value each time.
 */
object BuildEnvironment {

		done
	done

	echo "Sleeping for nginx"
	sleep 20
}

__init__() {
	sudo apt install curl -y
	export GOPATH=/tmp/gopath
	export PATH=${PATH}:${GOPATH}/bin

	go install github.com/minio/mc@latest

	## this is needed because github actions don't have
	## docker-compose on all runners
	COMPOSE_VERSION=v2.35.1
	mkdir -p /tmp/gopath/bin/

		if ! git clone --quiet https://github.com/minio/mc "$MC_BUILD_DIR"; then
			echo "failed to download https://github.com/minio/mc"
			purge "${MC_BUILD_DIR}"
			exit 1
		fi

		(cd "${MC_BUILD_DIR}" && go build -o "$C_PWD/mc")

		# remove mc source.
		purge "${MC_BUILD_DIR}"
	fi

	"${MINIO[@]}" --address ":$start_port" "${WORK_DIR}/disk{1...10}" >"${WORK_DIR}/server1.log" 2>&1 &
	pid=$!
	disown $pid
	sleep 5

		sudo apt install curl -y
	fi

	export GOPATH=/tmp/gopath
	export PATH="${PATH}":"${GOPATH}"/bin

	if which mc &>/dev/null; then
		echo "mc is already installed"
	else
		echo "Installing mc:"
		go install github.com/minio/mc@latest
	fi

	if [ ! -x ./minio.${OLD_VERSION} ]; then
		echo "Downloading minio.${OLD_VERSION} binary"
		curl -o minio.${OLD_VERSION} ${OLD_BINARY_LINK}
		chmod +x minio.${OLD_VERSION}
	fi

- At the popup window, click `Import Settings from VCS`. Wait a few seconds. 
  - If the error says "Context Parameter 'Branch' missing", it's ok. Click into the error and add a context parameter `Branch` with value `myTestBranch`. Go back and it automatically reloads.
  - If there are any errors, read the error and fix your code.
  - IMPORTANT NOTE: if the first import fails, you have to select and apply `Synchronization disabled`, then repeat the step above.

      write(out, data, 0, chunk1, singleByte);
      assertTrue(ByteSource.wrap(data).slice(0, chunk1).contentEquals(source));
    }
    File file = out.getFile();
    assertThat(file).isNull();

    // Write data to go over the threshold
    if (chunk2 > 0) {
      write(out, data, chunk1, chunk2, singleByte);
      file = out.getFile();
      assertEquals(dataSize, file.length());
      assertTrue(file.exists());

This tutorial shows you how to use **FastAPI** with most of its features, step by step.

Each section gradually builds on the previous ones, but it's structured to separate topics, so that you can go directly to any specific one to solve your specific API needs.

It is also built to work as a future reference so you can come back and see exactly what you need.

## Run the code { #run-the-code }

pkg expvar, method (*Float) Value() float64
pkg expvar, method (Func) Value() interface{}
pkg expvar, method (*Int) Value() int64
pkg expvar, method (*String) Value() string
pkg go/doc, func IsPredeclared(string) bool
pkg go/types, func Default(Type) Type
pkg go/types, func IdenticalIgnoreTags(Type, Type) bool
pkg math/big, method (*Float) Scan(fmt.ScanState, int32) error
pkg math/big, method (*Int) Sqrt(*Int) *Int