/**
     * OS family that can be tested for. {@value}
     */
    private static final String FAMILY_OS2 = "os/2";

    /**
     * OS family that can be tested for. {@value}
     */
    private static final String FAMILY_NETWARE = "netware";

    /**
     * OS family that can be tested for. {@value}
     */
    private static final String FAMILY_DOS = "dos";

    /**
     * OS family that can be tested for. {@value}

- Some base services that are available to code hosted by the runtime. This varies by runtime.
- Additional constraints. For example, the CLI client runtimes limit the libraries that are available to the code in that runtime, for performance reasons. 

Other modules and platforms define the services that they contribute to the runtime.

Instead, you want to provide a different dependency that will be used only during tests (possibly only some specific tests), and will provide a value that can be used where the value of the original dependency was used.

### Use cases: external service { #use-cases-external-service }

An example could be that you have an external authentication provider that you need to call.

You send it a token and it returns an authenticated user.

The **server** program (for example **Uvicorn** via **FastAPI CLI**) is capable of interpreting these headers, and then passing that information to your application.

import kotlin.reflect.KClass
import okio.IOException
import okio.Timeout

/**
 * A call is a request that has been prepared for execution. A call can be canceled. As this object
 * represents a single request/response pair (stream), it cannot be executed twice.
 */
interface Call : Cloneable {
  /** Returns the original request that initiated this call. */
  fun request(): Request

  /**

 * under the License.
 */
package org.apache.maven.building;

/**
 * Describes a problem that was encountered during settings building. A problem can either be an exception that was
 * thrown or a simple string message. In addition, a problem carries a hint about its source, e.g. the settings file
 * that exhibits the problem.
 *
 * @deprecated since 4.0.0, use {@link org.apache.maven.api.services} instead
 */

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build goexperiment.arenas

/*
The arena package provides the ability to allocate memory for a collection
of Go values and free that space manually all at once, safely. The purpose
of this functionality is to improve efficiency: manually freeing memory
before a garbage collection delays that cycle. Less frequent cycles means

# Middleware { #middleware }

You can add middleware to **FastAPI** applications.

A "middleware" is a function that works with every **request** before it is processed by any specific *path operation*. And also with every **response** before returning it.

* It takes each **request** that comes to your application.
* It can then do something to that **request** or run any needed code.

 * <ul>
 * <li>{@link Experimental}: Indicates that this interface or its implementation
 * may still be evolving and could change in future versions.</li>
 * <li>{@link FunctionalInterface}: Denotes that this is a functional interface,
 * allowing implementations as lambda expressions or method references.</li>
 * <li>{@link Consumer}: Signifies that this type is intended to be implemented

## Wildcards { #wildcards }

It's also possible to declare the list as `"*"` (a "wildcard") to say that all are allowed.

But that will only allow certain types of communication, excluding everything that involves credentials: Cookies, Authorization headers like those used with Bearer Tokens, etc.