"github.com/valyala/bytebufferpool"
)

// metadata stream format:
//
// The stream is s2 compressed.
// https://github.com/klauspost/compress/tree/master/s2#s2-compression
// This ensures integrity and reduces the size typically by at least 50%.
//
// All stream elements are msgpack encoded.
//
// 1 Integer, metacacheStreamVersion of the writer.
// This can be used for managing breaking changes.
//

 *       ImmutableMultiset#elementSet} iterate in the same order as the parent, except as noted.
 *   <li><b>Thread safety.</b> It is safe to access this collection concurrently from multiple
 *       threads.
 *   <li><b>Integrity.</b> This type cannot be subclassed outside this package (which would allow
 *       these guarantees to be violated).
 * </ul>
 *
 * <h4>"Interfaces", not implementations</h4>
 *

 *       ImmutableMultiset#elementSet} iterate in the same order as the parent, except as noted.
 *   <li><b>Thread safety.</b> It is safe to access this collection concurrently from multiple
 *       threads.
 *   <li><b>Integrity.</b> This type cannot be subclassed outside this package (which would allow
 *       these guarantees to be violated).
 * </ul>
 *
 * <h4>"Interfaces", not implementations</h4>
 *

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"

!!! check "Inspired **FastAPI** to"
    Adopt and use an open standard for API specifications, instead of a custom schema.

    And integrate standards-based user interface tools:

    * <a href="https://github.com/swagger-api/swagger-ui" class="external-link" target="_blank">Swagger UI</a>

    `Item(**item.dict(), owner_id=user_id)`

## Main **FastAPI** app

And now in the file `sql_app/main.py` let's integrate and use all the other parts we created before.

### Create the database tables

In a very simplistic way create the database tables:

=== "Python 3.9+"

    ```Python hl_lines="7"

And you can use directly many well maintained and widely used packages like `passlib` and `python-jose`, because **FastAPI** doesn't require any complex mechanisms to integrate external packages.

But it provides you the tools to simplify the process as much as possible without compromising flexibility, robustness, or security.