/// tip | Порада

   * remove()}. Otherwise, all optional operations are supported. Null row keys, columns keys, and
   * values are not supported.
   *
   * <p>Lookups by row key are often faster than lookups by column key, because the data is stored
   * in a {@code Map<R, Map<C, V>>}. A method call like {@code column(columnKey).get(rowKey)} still

		// be extra careful: Scanner is for safe, simple jobs.
		for loop := 0; ; {
			n, err := s.r.Read(s.buf[s.end:len(s.buf)])
			if n < 0 || len(s.buf)-s.end < n {
				s.setErr(ErrBadReadCount)
				break
			}
			s.end += n
			if err != nil {
				s.setErr(err)
				break
			}
			if n > 0 {
				s.empties = 0
				break
			}
			loop++
			if loop > maxConsecutiveEmptyReads {
				s.setErr(io.ErrNoProgress)

/// tip | Tipp

Wenn Sie einen `RuntimeError: Task attached to a different loop` erhalten, wenn Sie asynchrone Funktionsaufrufe in Ihre Tests integrieren (z. B. bei Verwendung von [MongoDBs MotorClient](https://stackoverflow.com/questions/41584243/runtimeerror-task-attached-to-a-different-loop)), dann denken Sie daran, Objekte zu instanziieren, die einen Event Loop nur innerhalb asynchroner Funktionen benötigen, z. B. einen `@app.on_event("startup")`-Callback.

	v := MSS{"abc": "def", "ghi": "jkl"}
	b.ReportAllocs()

	for b.Loop() {
		v.MarshalMsg(nil)
	}
}

func BenchmarkAppendMsgMSS(b *testing.B) {
	v := MSS{"abc": "def", "ghi": "jkl"}
	bts := make([]byte, 0, v.Msgsize())
	bts, _ = v.MarshalMsg(bts[0:0])
	b.SetBytes(int64(len(bts)))
	b.ReportAllocs()

	for b.Loop() {
		bts, _ = v.MarshalMsg(bts[0:0])
	}
}

    for prod and one for tests. However, unlike our other packages, as of this
    writing it has test supersource but no prod supersource.

    GWT happens to use the prod .gwt.xml, so it looks for no supersource for
    tests, either. This causes it to fail to find AtomicLongMapTest.

    Our workaround is to tell GWT that util.concurrent and all other packages

We are going to start from where we left in the previous chapter and increment it.

## About JWT { #about-jwt }

JWT means "JSON Web Tokens".

It's a standard to codify a JSON object in a long dense string without spaces. It looks like this:

```
eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c
```

    for prod and one for tests. However, unlike our other packages, as of this
    writing it has test supersource but no prod supersource.

    GWT happens to use the prod .gwt.xml, so it looks for no supersource for
    tests, either. This causes it to fail to find AtomicLongMapTest.

    Our workaround is to tell GWT that util.concurrent and all other packages

* and from it, import the function `get_token_header`.

But that file doesn't exist, our dependencies are in a file at `app/dependencies.py`.

Remember how our app/file structure looks like:

<img src="/img/tutorial/bigger-applications/package.drawio.svg">

---

The two dots `..`, like in:

```Python
from ..dependencies import get_token_header
```

mean:

* mount (noun): точка монтирования / mount (keep in English if it's a FastAPI keyword)
* plugin: плагин
* plug-in: плагин
* full stack: full stack (do not translate)
* full-stack: full-stack (do not translate)
* loop (as in async loop): цикл событий
* Machine Learning: Машинное обучение
* Deep Learning: Глубокое обучение
* callback hell: callback hell (clarify as `ад обратных вызовов`)
* on the fly: на лету