This code won't be executed in your app, we only need it to *document* how that *external API* should look like.

But, you already know how to easily create automatic documentation for an API with **FastAPI**.

So we are going to use that same knowledge to document how the *external API* should look like... by creating the *path operation(s)* that the external API should implement (the ones your API will call).

/// tip

For example, the `PATH` environment variable could look like this:

//// tab | Linux, macOS

```plaintext
/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin
```

This means that the system should look for programs in the directories:

* `/usr/local/bin`
* `/usr/bin`
* `/bin`
* `/usr/sbin`
* `/sbin`

////

/// tip

If you encounter a `RuntimeError: Task attached to a different loop` when integrating asynchronous function calls in your tests (e.g. when using <a href="https://stackoverflow.com/questions/41584243/runtimeerror-task-attached-to-a-different-loop" class="external-link" target="_blank">MongoDB's MotorClient</a>), remember to instantiate objects that need an event loop only within async functions, e.g. an `'@app.on_event("startup")` callback.

import (
	"errors"

	"github.com/minio/minio/internal/s3select/jstream"
	"github.com/minio/simdjson-go"
)

var (
	errKeyLookup                  = errors.New("Cannot look up key in non-object value")
	errIndexLookup                = errors.New("Cannot look up array index in non-array value")
	errWildcardObjectLookup       = errors.New("Object wildcard used on non-object value")

* Select "Python"
* Run the debugger with the option "`Python: Current File (Integrated Terminal)`".

It will then start the server with your **FastAPI** code, stop at your breakpoints, etc.

Here's how it might look:

<img src="/img/tutorial/debugging/image01.png">

---

If you use Pycharm, you can:

* Open the "Run" menu.
* Select the option "Debug...".
* Then a context menu shows up.

	res := jsonResult{}
	if err = json.Unmarshal([]byte(strings.ReplaceAll(jsonReq, "%%", "%")), &res); err != nil {
		t.Fatal(err)
	}

	// Look for expected method.
	if res.Method != http.MethodGet {
		t.Fatalf("Unexpected method %s, expected 'GET'", res.Method)
	}

	// Look for expected query values
	expectedQuery := url.Values{}
	expectedQuery.Set("prefix", "Hello*World*")

///

```

it would change the style to the default one, it would look like:

/// consejo

Esto es un consejo.

///

Those don't have to be translated, but if they are, they need to be written as:

```
/// tip | "consejo"

Esto es un consejo.

///

```

Which looks like:

/// tip | "consejo"

Esto es un consejo.

///

    return result;
  }

  /*
   * If I understand correctly:
   *
   * This needs to be a @JsMethod so that J2CL knows to look for a JavaScript implemention of
   * it in Platform.native.js. (The JavaScript implementation inline below is visible to *GWT*, but
   * *J2CL* doesn't look at it.)
   *
   * However, once it's a @JsMethod, GWT produces a warning. That's because (a) the *other* purpose

Because it is installed in the local project, you probably wouldn't be able to call that command directly, but you would put it on your `package.json` file.

It could look like this:

```JSON  hl_lines="7"
{
  "name": "frontend-app",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {

```

That means that the system would look for programs in:

* `/usr/bin`
* `/bin`
* `/usr/sbin`
* `/sbin`

////

//// tab | Windows

```plaintext
C:\Windows\System32
```

That means that the system would look for programs in:

* `C:\Windows\System32`

////

After activating the virtual environment, the `PATH` variable would look something like this: