The [Alias] type now has an [Rhs] method that returns the type on the
right-hand side of its declaration: given `type A = B`, the `Rhs` of A

### Core automation platform

This is a general-purpose automation platform which takes care of the efficient definition and execution of work, such as tasks.
This platform is agnostic to what exactly the purpose of the work is.
It might be creating an application, setting up development environments, orchestrating deployments, running simulations, etc.

don't have to do anything. The specific rules are [already bundled][okhttp3_pro] into the JAR which can be
interpreted by R8 automatically.

If you, however, don't use R8 you have to apply the rules from [this file][okhttp3_pro]. You might
also need rules from [Okio][okio] which is a dependency of this library.

 [okhttp3_pro]: https://raw.githubusercontent.com/square/okhttp/master/okhttp/src/main/resources/META-INF/proguard/okhttp3.pro

import java.io.IOException
import okhttp3.Interceptor
import okhttp3.Response
import okhttp3.internal.http.RealInterceptorChain

/**
 * Opens a connection to the target server and proceeds to the next interceptor. The network might
 * be used for the returned response, or to validate a cached response with a conditional GET.
 */
object ConnectInterceptor : Interceptor {
  @Throws(IOException::class)

class IntegrationTestFixtureVisitor : AbstractAstVisitor() {

    /**
     * Determines if the class is an integration test. It's a bit weak, but we cannot
     * rely on the class node analysis since it doesn't give the right superclass because
     * resolution is not complete when this visitor is executed.
     */
    private
    fun isIntegrationTest(current: ClassNode) = current.name.endsWith("Test")
        || current.name.endsWith("Spec")

The benefit of raising an exception over `return`ing a value will be more evident in the section about Dependencies and Security.

# Global Dependencies

For some types of applications you might want to add dependencies to the whole application.

Similar to the way you can [add `dependencies` to the *path operation decorators*](dependencies-in-path-operation-decorators.md){.internal-link target=_blank}, you can add them to the `FastAPI` application.

In that case, they will be applied to all the *path operations* in the application:

=== "Python 3.9+"

    ```Python hl_lines="16"

              UnknownHostException(e.message).apply {
                initCause(e)
              },
            )
          }
        },
      )
    } catch (e: Exception) {
      // Handle any errors that might leak out
      // https://issuetracker.google.com/issues/319957694
      callback.onFailure(
        hostname,
        UnknownHostException(e.message).apply {
          initCause(e)
        },
      )
    }
  }

But first, let's check some small concepts.

## In a hurry?

If you don't care about any of these terms and you just need to add security with authentication based on username and password *right now*, skip to the next chapters.

## OAuth2

OAuth2 is a specification that defines several ways to handle authentication and authorization.

It is quite an extensive specification and covers several complex use cases.

* Implement and use well-known cryptographic tools, like Passlib and JWT tokens, etc.
* Add more granular permission controls with OAuth2 scopes where needed.
* ...etc.

Nevertheless, you might have a very specific use case where you really need to disable the API docs for some environment (e.g. for production) or depending on configurations from environment variables.

## Conditional OpenAPI from settings and env vars