"""
    Create an invoice.

    This will (let's imagine) let the API user (some external developer) create an
    invoice.

    And this path operation will:

    * Send the invoice to the client.
    * Collect the money from the client.
    * Send a notification back to the API user (the external developer), as a callback.
        * At this point is that the API will somehow send a POST request to the

    If you want to read more about these encodings and form fields, head to the <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/POST" class="external-link" target="_blank"><abbr title="Mozilla Developer Network">MDN</abbr> web docs for <code>POST</code></a>.

!!! warning

Ostatnia ankieta <abbr title="coroczna ankieta przeprowadza w środowisku programistów języka Python">Python developer survey</abbr> jasno wskazuje, że <a href="https://www.jetbrains.com/research/python-developers-survey-2017/#tools-and-features" class="external-link" target="_blank">najczęściej używaną funkcjonalnością jest autouzupełnianie w edytorze</a>.

## Recap

Having **HTTPS** is very important, and quite **critical** in most cases. Most of the effort you as a developer have to put around HTTPS is just about **understanding these concepts** and how they work.

But once you know the basic information of **HTTPS for developers** you can easily combine and configure different tools to help you manage everything in a simple way.

It uses Marshmallow underneath to do the data validation. And it was created by the same developers.

It's a great tool and I have used it a lot too, before having **FastAPI**.

!!! info
    Webargs was created by the same Marshmallow developers.

!!! check "Inspired **FastAPI** to"
    Have automatic validation of incoming request data.

**FastAPI** has a very powerful but intuitive **<abbr title="also known as components, resources, providers, services, injectables">Dependency Injection</abbr>** system.

It is designed to be very simple to use, and to make it very easy for any developer to integrate other components with **FastAPI**.

## What is "Dependency Injection"

    Если вы хотите узнать больше об этих кодировках и полях форм, перейдите по ссылке <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/POST" class="external-link" target="_blank"><abbr title="Mozilla Developer Network">MDN</abbr> web docs for <code>POST</code></a>.

!!! warning "Внимание"

Trong lần khảo sát cuối cùng dành cho các lập trình viên Python, đã rõ ràng <a href="https://www.jetbrains.com/research/python-developers-survey-2017/#tools-and-features" class="external-link" target="_blank">rằng đa số các lập trình viên sử dụng tính năng "autocompletion"</a>.

* **Fast to code**: Increase the speed to develop features by about 200% to 300%. *
* **Fewer bugs**: Reduce about 40% of human (developer) induced errors. *
* **Intuitive**: Great editor support. <abbr title="also known as auto-complete, autocompletion, IntelliSense">Completion</abbr> everywhere. Less time debugging.

!!! note "Technical Details"
    You could also use `from starlette.responses import HTMLResponse`.

    **FastAPI** provides the same `starlette.responses` as `fastapi.responses` just as a convenience for you, the developer. But most of the available responses come directly from Starlette.

### `Response`

The main `Response` class, all the other responses inherit from it.

You can return it directly.