/**
     * Returns an error for the DNS query.
     */
    fun onFailure(
      hostname: String,
      e: IOException,
    )
  }

  /**
   * Class of DNS addresses, such that clients that treat these differently, such
   * as attempting IPv6 first, can make such decisions.
   */
  @ExperimentalOkHttpApi
  enum class DnsClass(val type: Int) {
    IPV4(TYPE_A),
    IPV6(TYPE_AAAA),
  }

# Treat all files in the Go repo as binary, with no git magic updating
# line endings. This produces predictable results in different environments.
#
# Windows users contributing to Go will need to use a modern version
# of git and editors capable of LF line endings.
#
# Windows .bat files are known to have multiple bugs when run with LF
# endings, and so they are checked in with CRLF endings, with a test

   */
  @ExperimentalOkHttpApi
  fun setPolicy(
    address: Address,
    policy: AddressPolicy,
  ) {
    delegate.setPolicy(address, policy)
  }

  /**
   * A policy for how the pool should treat a specific address.
   */
  class AddressPolicy(
    /**
     * How many concurrent calls should be possible to make at any time.

* Typed clients (via generics) and more ergonomic APIs
* Ability to make a _delayed_ client. This is used when making clients based on CRDs that may not exist.
  In general, Istio does not fail on missing CRDs and prefers to treat these as if there were just zero resources for that client.
  The `NewDelayedInformer` abstracts that entirely, offering the same API as normal `kclient.Client`.

  // time for any reason.  Missed jobs executions will be counted as failed ones.
  // +optional
  optional int64 startingDeadlineSeconds = 2;

  // Specifies how to treat concurrent executions of a Job.
  // Valid values are:
  //
  // - "Allow" (default): allows CronJobs to run concurrently;
  // - "Forbid": forbids concurrent runs, skipping next run if previous run hasn't finished yet;

If you declare it as is, because it is a singular value, **FastAPI** will assume that it is a query parameter.

But you can instruct **FastAPI** to treat it as another body key using `Body`:

=== "Python 3.10+"

    ```Python hl_lines="23"
    {!> ../../../docs_src/body_multiple_params/tutorial003_an_py310.py!}
    ```

=== "Python 3.9+"

## 1. Prerequisites

* Familiarity with [Docker Compose](https://docs.docker.com/compose/overview/).

As part of that, I needed to investigate, test and use many alternatives.

The history of **FastAPI** is in great part the history of its predecessors.

As said in the section [Alternatives](alternatives.md){.internal-link target=_blank}:

<blockquote markdown="1">

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

Up to now, you have been using common data types, like:

* `int`
* `float`
* `str`
* `bool`

But you can also use more complex data types.

And you will still have the same features as seen up to now:

* Great editor support.
* Data conversion from incoming requests.
* Data conversion for response data.
* Data validation.
* Automatic annotation and documentation.

## Other data types

=================

Thank you so much for wanting to contribute to Guava! Here are a few important
things you should know about contributing:

1.  API changes require discussion, use cases, etc. Code comes later.
2.  Pull requests are great for small fixes for bugs, documentation, etc.
3.  Pull requests are not merged directly into the master branch.
4.  Code contributions require signing a Google CLA.

API changes
-----------