We could create an instance of this class with:

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[18] *}

And that way we are able to "parameterize" our dependency, that now has `"bar"` inside of it, as the attribute `checker.fixed_content`.

## Use the instance as a dependency { #use-the-instance-as-a-dependency }

///

## Crear un middleware

Para crear un middleware usas el decorador `@app.middleware("http")` encima de una función.

La función middleware recibe:

* La `request`.
* Una función `call_next` que recibirá la `request` como parámetro.
    * Esta función pasará la `request` a la correspondiente *path operation*.

ction(e){var n=e.state,r=e.instance,o=e.options,i=o.scroll,a=void 0===i||i,s=o.resize,f=void 0===s||s,c=t(n.elements.popper),p=[].concat(n.scrollParents.reference,n.scrollParents.popper);return a&&p.forEach((function(e){e.addEventListener("scroll",r.update,$)})),f&&c.addEventListener("resize",r.update,$),function(){a&&p.forEach((function(e){e.removeEventListener("scroll",r.update,$)})),f&&c.removeEventListener("resize",r.update,$)}},data:{}};var te={name:"popperOffsets",enabled:!0,phase:"read",fn:function(e){var...

This won't happen if you import that module (file).

So, if you have another file `importer.py` with:

```Python
from myapp import app

# Some more code
```

in that case, the automatically created variable inside of `myapp.py` will not have the variable `__name__` with a value of `"__main__"`.

So, the line:

```Python
    uvicorn.run(app, host="0.0.0.0", port=8000)
```

will not be executed.

/// info

# above is tagged with "py3-none-any". We cannot change the tags by simply
# renaming the wheels as uploading to PyPI would fail with "File already exists"
# error. In order to upload to PyPI, we unpack the wheel and change the tag
# inside a metadata file to the one we want (e.g cp38-cp38-win_amd) and then
# re-pack it to generate it as a platform specific wheel with this new wheel
#tag.
python3 -m wheel unpack "${pure_python_whl}"

    try {
      return fromValid(specifier);
    } catch (IllegalArgumentException e) {
      // Since the IAE can originate at several different points inside
      // fromValid(), we implement this method in terms of that one rather
      // than the reverse.

      ParseException parseException = new ParseException("Invalid host specifier: " + specifier, 0);

You can use `async def` or normal `def`.

And you can declare dependencies with `async def` inside of normal `def` *path operation functions*, or `def` dependencies inside of `async def` *path operation functions*, etc.

It doesn't matter. **FastAPI** will know what to do.

/// note

{* ../../docs_src/path_params/tutorial002.py hl[7] *}

In this case, `item_id` is declared to be an `int`.

/// check

This will give you editor support inside of your function, with error checks, completion, etc.

///

## Data <abbr title="also known as: serialization, parsing, marshalling">conversion</abbr> { #data-conversion }

{* ../../docs_src/path_operation_configuration/tutorial003.py hl[20:21] *}

## 📛 ⚪️➡️ #️⃣

📛 😑 📏 &amp; 📔 💗 ⏸, 👆 💪 📣 *➡ 🛠️* 📛 🔢 <abbr title="a multi-line string as the first expression inside a function (not assigned to any variable) used for documentation"> #️⃣ </abbr> &amp; **FastAPI** 🔜 ✍ ⚫️ ⚪️➡️ 📤.

 * conformance of concrete {@link SortedMap} subclasses to that contract.
 *
 * @author Jared Levy
 */
// TODO: Use this class to test classes besides ImmutableSortedMap.
@GwtCompatible
public abstract class SortedMapInterfaceTest<K, V> extends MapInterfaceTest<K, V> {

  protected SortedMapInterfaceTest(
      boolean allowsNullKeys,
      boolean allowsNullValues,