Supplier<Integer> fiveSupplier =
        new Supplier<Integer>() {
          @Override
          public Integer get() {
            return 5;
          }
        };

    Function<Number, Integer> intValueFunction =
        new Function<Number, Integer>() {
          @Override
          public Integer apply(Number x) {
            return x.intValue();
          }
        };

    Supplier<Integer> fiveSupplier =
        new Supplier<Integer>() {
          @Override
          public Integer get() {
            return 5;
          }
        };

    Function<Number, Integer> intValueFunction =
        new Function<Number, Integer>() {
          @Override
          public Integer apply(Number x) {
            return x.intValue();
          }
        };

* `"request"`: start the dependency before the *path operation function* that handles the request (similar to when using `"function"`), but end **after** the response is sent back to the client. So, the dependency function will be executed **around** the **request** and response...

 */

package com.google.common.util.concurrent;

import com.google.common.base.Function;
import java.util.concurrent.Executor;
import org.jspecify.annotations.Nullable;

/**
 * Hidden superclass of {@link Futures} that provides us a place to declare special GWT versions of
 * the {@link Futures#catching(ListenableFuture, Class, com.google.common.base.Function)
 * Futures.catching} family of methods. Those versions have slightly different signatures.

            Doc(
                """
                The function to call after the response is sent.

                It can be a regular `def` function or an `async def` function.
                """
            ),
        ],
        *args: P.args,
        **kwargs: P.kwargs,
    ) -> None:
        """
        Add a function to be called in the background after the response is sent.

   */
  public final <T extends @Nullable Object> FluentIterable<T> transform(
      Function<? super E, T> function) {
    return from(Iterables.transform(getDelegate(), function));
  }

  /**
   * Applies {@code function} to each element of this fluent iterable and returns a fluent iterable
   * with the concatenated combination of results. {@code function} returns an Iterable of results.
   *

    }

    /**
     * Processes virtual host configuration by applying a function to the matched virtual host key.
     *
     * @param <T> The return type of the function
     * @param func The function to apply to the virtual host key
     * @param defaultValue The default value to return if no virtual host matches
     * @return The result of applying the function, or the default value
     */

// Cache contains a synchronized value that is considered valid
// for a specific amount of time.
// An Update function must be set to provide an updated value when needed.
type Cache[T any] struct {
	// updateFn must return an updated value.
	// If an error is returned the cached value is not set.
	// Only one caller will call this function at any time, others will be blocking.
	// The returned value can no longer be modified once returned.

   * Not supported. Use {@link #toImmutableBiMap} instead. This method exists only to hide {@link
   * ImmutableMap#toImmutableMap(Function, Function)} from consumers of {@code ImmutableBiMap}.
   *
   * @throws UnsupportedOperationException always
   * @deprecated Use {@link ImmutableBiMap#toImmutableBiMap(Function, Function)}.
   * @since 33.2.0 (available since 21.0 in guava-jre)
   */
  @Deprecated
  @DoNotCall("Use toImmutableBiMap")

  @Override
  public Set<T> asSet() {
    return Collections.singleton(reference);
  }

  @Override
  public <V> Optional<V> transform(Function<? super T, V> function) {
    return new Present<>(
        checkNotNull(
            function.apply(reference),
            "the Function passed to Optional.transform() must not return null."));
  }

  @Override
  public boolean equals(@Nullable Object obj) {