@Deprecated
@Beta
@GwtCompatible
public abstract class TreeTraverser<T> {
  /** Constructor for use by subclasses. */
  public TreeTraverser() {}

  /**
   * Returns a tree traverser that uses the given function to navigate from a node to its children.
   * This is useful if the function instance already exists, or so that you can supply a lambda

        switch (variant) {
        case DEFAULT_WITH_PS: {
            JAASAuthenticator a = new JAASAuthenticator();
            // Provide a preset Subject so the getSubject() path uses the (serviceName, ps, this) constructor
            a.setSubject(new Subject());
            return a;
        }
        case WITH_CONFIG: {

   * href="https://docs.oracle.com/javase/tutorial/java/generics/genTypeInference.html#type-inference-instantiation">"diamond"
   * syntax</a>. One caveat to this is that the {@code TreeSet} constructor uses a null {@code
   * Comparator} to mean "natural ordering," whereas this factory rejects null. Clean your code
   * accordingly.
   *
   * @param comparator the comparator to use to sort the set

Webargs is a tool that was made to provide that on top of several frameworks, including Flask.

It uses Marshmallow underneath to do the data validation. And it was created by the same developers.

It's a great tool and I have used it a lot too, before having **FastAPI**.

/// info

import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

/**
 * Base class for services that can implement {@link #startUp}, {@link #run} and {@link #shutDown}
 * methods. This class uses a single thread to execute the service; consider {@link AbstractService}
 * if you would like to manage any threading manually.
 *
 * @author Jesse Wilson
 * @since 1.0
 */
@GwtIncompatible
@J2ktIncompatible

 *       complicate debugging, lead to unintentional reentrant calls, and force apps to eagerly
 *       initialize all possible subscribers at startup time.
 *   <li>It uses reflection in ways that break when code is processed by optimizers/minimizers like
 *       <a href="https://developer.android.com/studio/build/shrink-code">R8 and Proguard</a>.

///

{* ../../docs_src/settings/tutorial001_pv1.py hl[2,5:8,11] *}

////

/// tip | Consejo

Si quieres algo rápido para copiar y pegar, no uses este ejemplo, usa el último más abajo.

///

    private static final String HANDLER_PKGS_PROPERTY = "java.protocol.handler.pkgs";

    /**
     * Vendor-specific default packages. If no packages are specified in
     * "java.protocol.handler.pkgs", the VM uses one or more default
     * packages, which are vendor specific. Sun's is included below
     * for convenience; others could be as well. If a particular vendor's
     * package isn't listed, it can be specified in

            // which was set when the class was loaded
            TimeZone providedTimeZone = provider.provide();
            assertNotNull(providedTimeZone);
            // The provider uses the static centralTimeZone which captures the original default
            assertEquals(originalDefault, providedTimeZone);
        } finally {
            // Restore original timezone

# Body - Multiple Parameters { #body-multiple-parameters }

Now that we have seen how to use `Path` and `Query`, let's see more advanced uses of request body declarations.

## Mix `Path`, `Query` and body parameters { #mix-path-query-and-body-parameters }

First, of course, you can mix `Path`, `Query` and request body parameter declarations freely and **FastAPI** will know what to do.