* 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 { #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**.

## Use Case { #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. 🤖

/// 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"])

...it has the same parameters as our previous `common_parameters`:

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[8] *}

Those parameters are what **FastAPI** will use to "solve" the dependency.

In both cases, it will have:

* An optional `q` query parameter that is a `str`.
* A `skip` query parameter that is an `int`, with a default of `0`.

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 { #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.

       * work under Android.
       *
       * (Clearing inheritableThreadLocals could still be useful independent of class unloading, but
       * that's a larger problem, which we don't attempt to solve anywhere else in Guava.)
       */
      return null;
    }
    try {
      Field inheritableThreadLocals = Thread.class.getDeclaredField("inheritableThreadLocals");
      inheritableThreadLocals.setAccessible(true);

In discussions and PRs, in many cases, people bring their frustration and show it without filter, in many cases exaggerating, complaining, being entitled, etc. That's really not nice, and when it happens, it lowers our priority to solve their problems. But still, try to breath, and be gentle with your answers.

Try to avoid using bitter sarcasm or potentially passive-aggressive comments. If something is wrong, it's better to be direct (try to be gentle) than sarcastic.

---
title: Recipes
description: A collection of common/useful code examples for Kotlin and Java
---


# Recipes

We've written some recipes that demonstrate how to solve common problems with OkHttp. Read through them to learn about how everything works together. Cut-and-paste these examples freely; that's what they're for.

### Synchronous Get ([.kt][SynchronousGetKotlin], [.java][SynchronousGetJava])

   * one input completes with result X and another later with result Y, for Y to come before X in
   * the output future list. (Such races are impossible to solve without global synchronization of
   * all future completions. And they should have little practical impact.)
   *
   * <p>Cancelling a delegate future propagates to input futures once all the delegates complete,