#### JVM platform

This is a platform that builds on the core and software platforms to add support for developing software that runs on the JVM.
This includes software that is implemented using Java, Kotlin or some other JVM language.

This platform provides specific support for Java, Groovy and Scala, and includes the foojay toolchain plugin. 

#### Extensibility platform

!!! tip
    Notice that here as we are using standard `open()` that doesn't support `async` and `await`, we declare the path operation with normal `def`.

### `FileResponse`

Asynchronously streams a file as the response.

Takes a different set of arguments to instantiate than the other response types:

  //
  // The value of this field can be more than 100, implying that this
  // priority level can borrow a number of seats that is greater than
  // its own nominal concurrency limit (NominalCL).
  // When this field is left `nil`, the limit is effectively infinite.
  // +optional
  optional int32 borrowingLimitPercent = 4;
}

// NonResourcePolicyRule is a predicate that matches non-resource requests according to their verb and the

 * Tasks execute with the same happens-before order that the function calls to {@link #submit} and
 * {@link #submitAsync} that submitted those tasks had.
 *
 * <p>This class has limited support for cancellation and other "early completions":
 *
 * <ul>
 *   <li>While calls to {@code submit} and {@code submitAsync} return a {@code Future} that can be
 *       cancelled, cancellation never propagates to a task that has started to run -- neither to

## 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.

It includes ways to authenticate using a "third party".

That's what all the systems with "login with Facebook, Google, Twitter, GitHub" use underneath.

### OAuth 1

   * cannot implement that interface in source code in a way that will compile on both Java 7 and
   * Java 8. If we include the {@code getAnnotatedBounds()} method then its return type means it
   * won't compile on Java 7, while if we don't include the method then the compiler will complain

/**
 * A set of worker threads that are shared among a set of task queues.
 *
 * Use [INSTANCE] for a task runner that uses daemon threads. There is not currently a shared
 * instance for non-daemon threads.
 *
 * The task runner is also responsible for releasing held threads when the library is unloaded.
 * This is for the benefit of container environments that implement code unloading.
 *

name is a type or an ordinary identifier, so there will be no syntax
errors that might stop parsing early.

An error on not-declared:1 indicates that foo is undeclared.
An error on not-type:1 indicates that foo is not a type (if declared at all, it is an identifier).
An error on not-int-const:1 indicates that foo is not an integer constant.
An error on not-num-const:1 indicates that foo is not a number constant.

  // a map of client CIDR to server address that is serving this group.
  // This is to help clients reach servers in the most network-efficient way possible.
  // Clients can use the appropriate server address as per the CIDR that they match.
  // In case of multiple matches, clients should use the longest matching CIDR.
  // The server returns only those CIDRs that it thinks that the client can match.

ItemsService.createItemItemsPost({name: "Plumbus", price: 5})
```

...that's because the client generator uses the OpenAPI internal **operation ID** for each *path operation*.

OpenAPI requires that each operation ID is unique across all the *path operations*, so FastAPI uses the **function name**, the **path**, and the **HTTP method/operation** to generate that operation ID, because that way it can make sure that the operation IDs are unique.