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, X (Twitter), GitHub" use underneath.

### OAuth 1 { #oauth-1 }

It means that **FastAPI** was specifically tested with the editors used by 80% of the Python developers. And as most of the other editors tend to work similarly, all its benefits should work for virtually all editors.

That way I could find the best ways to reduce code duplication as much as possible, to have completion everywhere, type and error checks, etc.

import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Dispatches events to listeners, and provides ways for listeners to register themselves.
 *
 * <h2>Avoid EventBus</h2>
 *
 * <p><b>We recommend against using EventBus.</b> It was designed many years ago, and newer
 * libraries offer better ways to decouple components and react to events.
 *

// any pointer.
type uintptr uintptr

// byte is an alias for uint8 and is equivalent to uint8 in all ways. It is
// used, by convention, to distinguish byte values from 8-bit unsigned
// integer values.
type byte = uint8

// rune is an alias for int32 and is equivalent to int32 in all ways. It is
// used, by convention, to distinguish character values from integer values.
type rune = int32

import com.google.caliper.Benchmark;
import com.google.caliper.Param;
import java.util.ArrayList;
import java.util.List;
import org.jspecify.annotations.NullUnmarked;

/**
 * Benchmark for various ways to create an {@code ImmutableList}.
 *
 * @author Louis Wasserman
 */
@NullUnmarked
public class ImmutableListCreationBenchmark {

  @Param({"10", "1000", "1000000"})
  int size;

            QueryOp.create(
                "count",
                (ms, o) -> {
                  int unused = ms.count(o);
                },
                Math::log)));
  }

  /** All the ways to create an ImmutableMultiset. */
  enum ConstructionPathway implements Construction<Multiset<Object>> {
    COPY_OF_COLLECTION {
      @Override
      public ImmutableMultiset<Object> create(List<?> keys) {

## Deployment Strategies { #deployment-strategies }

There are several ways to do it depending on your specific use case and the tools that you use.

{* ../../docs_src/request_forms/tutorial001_an_py39.py hl[3] *}

## Define `Form` parameters { #define-form-parameters }

Create form parameters the same way you would for `Body` or `Query`:

{* ../../docs_src/request_forms/tutorial001_an_py39.py hl[9] *}

For example, in one of the ways the OAuth2 specification can be used (called "password flow") it is required to send a `username` and `password` as form fields.

import com.google.caliper.BeforeExperiment;
import com.google.caliper.Benchmark;
import com.google.caliper.Param;
import java.util.Random;
import org.jspecify.annotations.NullUnmarked;

/**
 * Benchmarks for various ways of writing the expression {@code foo + ((bar < baz) ? 1 : 0)}.
 *
 * @author Louis Wasserman
 */
@NullUnmarked
public class LessThanBenchmark {
  static final int SAMPLE_SIZE = 0x1000;

 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
public class ListenableFutureTask<V extends @Nullable Object> extends FutureTask<V>
    implements ListenableFuture<V> {
  // TODO(cpovirk): explore ways of making ListenableFutureTask final. There are some valid reasons
  // such as BoundedQueueExecutorService to allow extends but it would be nice to make it final to
  // avoid unintended usage.