## 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. 🤖

You can declare extra information in `Field`, `Query`, `Body`, etc. And it will be included in the generated JSON Schema.

You will learn more about adding extra information later in the docs, when learning to declare examples.

/// warning

Extra keys passed to `Field` will also be present in the resulting OpenAPI schema for your application.

---

### 🎓 **Learning Resources for Gradle**

Kickstart your Gradle knowledge with courses, guides, and community support tailored to various experience levels:

- **[DPE University Free Courses](https://dpeuniversity.gradle.com/app/catalog)**: A collection of hands-on courses for learning Gradle, complete with project-based tasks to improve real-world skills.

        token: ${{ secrets.JENKINS_TOKEN }}
        base: ${{ github.event.inputs.release_branch }}
        branch: ${{ github.event.inputs.release_branch }}-${{ steps.cherrypick.outputs.SHORTSHA }}
        reviewers: learning-to-play
        body: |

        title: Update the RBE images to the latest container versions
        committer: TensorFlow Release Automation <******@****.***>
        token: ${{ secrets.JENKINS_TOKEN }}
        reviewers: mihaimaruseac,learning-to-play,nitins17
        body: |
          This PR was created by a GitHub Actions workflow to update all the SIG Build-based RBE containers to the most recent containers. See:

# Tests

tf_cuda_library(
    name = "c_test_util",
    testonly = 1,
    srcs = ["c_test_util.cc"],
    hdrs = ["c_test_util.h"],
    visibility = [
        "//learning/brain:__subpackages__",
        "//tensorflow:__subpackages__",
    ],
    deps = [
        ":c_api",
        ":c_api_experimental",
        "//tensorflow/core:lib",
        "//tensorflow/core:protos_all_cc",

**FastAPI** is all based on these type hints, they give it many advantages and benefits.

But even if you never use **FastAPI**, you would benefit from learning a bit about them.

/// note

If you are a Python expert, and you already know everything about type hints, skip to the next chapter.

///

## Motivation

Let's start with a simple example:

* 📝 Add external link: Building simple E-Commerce with NuxtJS and FastAPI. PR [#3271](https://github.com/tiangolo/fastapi/pull/3271) by [@ShahriyarR](https://github.com/ShahriyarR).
* 📝 Add external link: Serve a machine learning model using Sklearn, FastAPI and Docker. PR [#2974](https://github.com/tiangolo/fastapi/pull/2974) by [@rodrigo-arenas](https://github.com/rodrigo-arenas).

            }

            validateStringNoExpression("groupId", problems, Severity.WARNING, Version.V20, m.getGroupId(), m);
            if (parent == null) {
                validateStringNotEmpty("groupId", problems, Severity.FATAL, Version.V20, m.getGroupId(), m);
            }

            validateStringNoExpression("artifactId", problems, Severity.WARNING, Version.V20, m.getArtifactId(), m);

    // notice to self: what was this method supposed to do?
    //
    /**
     * <b>Warning</b>: ignored.
     */
    public void returnComponentLogger(String role) {}

    /**
     * <b>Warning</b>: ignored.
     */
    public void returnComponentLogger(String role, String hint) {}

    /**
     * <b>Warning</b>: ignored (always return <code>0</code>).
     */
    public int getThreshold() {
        return 0;