* In many cases, it's better to understand their **underlying problem or use case**, because there might be a better way to solve it than what they are trying to do.

### Ask to close

If they reply, there's a high chance you would have solved their problem, congrats, **you're a hero**! 🦸

* Now, if that solved their problem, you can ask them to:

    * In GitHub Discussions: mark the comment as the **answer**.

    // IDE tries to acquire its bytecode via the index, however,
    // the index doesn't cover classfiles from compiler output,
    // so the lowering fails.
    //
    // To solve the problem, we need to find all delegated properties with inline accessors
    // reachable from files that will be compiled, and include files these inline accessors

## Use Case

Let's start with an example **use case** and then see how to solve it with this.

Let's imagine that you have some **machine learning models** that you want to use to handle requests. 🤖

  - org:foo between versions 1.1 and 1.0"""
        failure.assertHasResolutions("Run with :dependencyInsight --configuration conf " +
            "--dependency org:foo to get more insight on how to solve the conflict.",
            STACKTRACE_MESSAGE,
            INFO_DEBUG,
            SCAN,
            GET_HELP
        )
    }

But because of our changes in `GzipRequest.body`, the request body will be automatically decompressed when it is loaded by **FastAPI** when needed.

## Accessing the request body in an exception handler

!!! tip
    To solve this same problem, it's probably a lot easier to use the `body` in a custom handler for `RequestValidationError` ([Handling Errors](../tutorial/handling-errors.md#use-the-requestvalidationerror-body){.internal-link target=_blank}).

    ```

!!! info
    Notice that we are only declaring one dependency in the *path operation function*, the `query_or_cookie_extractor`.

    But **FastAPI** will know that it has to solve `query_extractor` first, to pass the results of that to `query_or_cookie_extractor` while calling it.

```mermaid
graph TB

query_extractor(["query_extractor"])

     *
     * @param details the details
     * @return this
     * @since 8.6
     */
    ProblemSpec details(String details);

    /**
     * A description of how to solve this problem.
     *
     * @param solution the solution.
     * @return this
     * @since 8.6
     */
    ProblemSpec solution(String solution);

    /**
     * The exception causing this problem.

          <!-- We add the link ourselves, both so that we can choose Java 9 over the version that -source suggests and so that we can solve the JSR305 problem described below. -->
          <detectJavaApiLink>false</detectJavaApiLink>
          <offlineLinks>

This tutorial shows you how to use **FastAPI** with most of its features, step by step.

Each section gradually builds on the previous ones, but it's structured to separate topics, so that you can go directly to any specific one to solve your specific API needs.

It is also built to work as a future reference.

So you can come back and see exactly what you need.

## Run the code

**FastAPI** wouldn't exist if not for the previous work of others.

There have been many tools created before that have helped inspire its creation.

I have been avoiding the creation of a new framework for several years. First I tried to solve all the features covered by **FastAPI** using many different frameworks, plug-ins, and tools.