3. Copy the file with the requirements to the `/code` directory.

    Copy **only** the file with the requirements first, not the rest of the code.

    As this file **doesn't change often**, Docker will detect it and use the **cache** for this step, enabling the cache for the next step too.

4. Install the package dependencies in the requirements file.

                log.debug(String.format("Retrying (%d/%d) request %s", retries, maxRetries, request));
            }

            // should we disconnect the transport here? otherwise we make an additional attempt to detect that if the
            // server closed the connection as a result
            log.debug("Disconnecting tree on send retry", last);
            disconnect(true);

            if (retries >= maxRetries) {

    response1.close()

    // Force a fresh connection for the next request.
    client.connectionPool.evictAll()

    // Confirm that a second request also succeeds. This should detect caching problems.
    server.enqueue(
      MockResponse
        .Builder()
        .body("def")
        .onResponseEnd(ShutdownConnection)
        .build(),
    )
    val call2 =

INFO:     Application startup complete.
```

</div>

<details markdown="1">
<summary>About the command <code>fastapi dev main.py</code>...</summary>

The command `fastapi dev` reads your `main.py` file, detects the **FastAPI** app in it, and starts a server using <a href="https://www.uvicorn.org" class="external-link" target="_blank">Uvicorn</a>.

By default, `fastapi dev` will start with auto-reload enabled for local development.

   * 'affect' a bit(j) in the output if two inputs, identical but for bit(i), will differ at output
   * bit(j) about half the time
   *
   * <p>Funneling is pretty simple to detect. The key idea is to find example keys which
   * unequivocally demonstrate that funneling cannot be occurring. This is done bit-by-bit. For each

        </field>
      </fields>
    </class>
    <class java.clone="deep">
      <name>ActivationOS</name>
      <version>1.0.0+</version>
      <description>
        This is an activator which will detect an operating system's attributes in order to activate
        its profile.
      </description>
      <fields>
        <field>
          <name>name</name>
          <version>1.0.0+</version>

de la manera descrita anteriormente y estás acostumbrado a definir funciones de *path operation* solo de cómputo trivial con `def` normal para una pequeña ganancia de rendimiento (alrededor de 100 nanosegundos), ten en cuenta que en **FastAPI** el efecto sería bastante opuesto. En estos casos, es mejor usar `async def` a menos que tus *path operation functions* usen código que realice <abbr title="Input/Output: lectura o escritura en disco, comunicaciones de red.">I/O</abbr> de bloqueo.

Aun...

```Python hl_lines="1  4"
{!../../docs_src/python_types/tutorial009.py!}
```

Using `Optional[str]` instead of just `str` will let the editor help you detect errors where you could be assuming that a value is always a `str`, when it could actually be `None` too.

`Optional[Something]` is actually a shortcut for `Union[Something, None]`, they are equivalent.

query.highlight.phrase.limit=256
# Fields for content description in query highlighting.
query.highlight.content.description.fields=hl_content,digest
# Whether to detect boundary position in query highlighting.
query.highlight.boundary.position.detect=true
# Type for text fragment in query highlighting.
query.highlight.text.fragment.type=query
# Size for text fragment in query highlighting.
query.highlight.text.fragment.size=3

       *
       * - ServiceDelegate.runningTask contains an instance of ReschedulableCallable (at least in
       *   the case that the service is using CustomScheduler). (It needs it so that it can cancel
       *   the task and detect whether it has been cancelled.)
       *
       * - ReschedulableCallable has a reference back to its enclosing CustomScheduler. (It needs it
       *   so that it can call getNextSchedule).
       *