public CustomScheduler() {}

    /** A callable class that can reschedule itself using a {@link CustomScheduler}. */
    private final class ReschedulableCallable implements Callable<@Nullable Void> {

      /** The underlying task. */
      private final Runnable wrappedRunnable;

      /** The executor on which this Callable will be scheduled. */
      private final ScheduledExecutorService executor;

    fakeTicker = new FakeTicker();
  }

  @Test
  public void loader() throws ExecutionException {
    Cache<Integer, Integer> cache = CacheBuilder.newBuilder().build();

    Callable<Integer> loader =
        new Callable<Integer>() {
          private int i = 0;

          @Override
          public Integer call() throws Exception {
            return ++i;
          }
        };

    cache.put(0, 10);

from collections.abc import Iterable, Mapping
from enum import Enum
from typing import Annotated, Any, Callable, Optional, Union

from fastapi._compat import with_info_plain_validator_function
from fastapi.logger import logger
from pydantic import (
    AnyUrl,
    BaseModel,
    Field,
    GetJsonSchemaHandler,
)
from typing_extensions import Literal, TypedDict
from typing_extensions import deprecated as typing_deprecated

try:

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.ImmutableMap;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.Callable;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ExecutionException;

/**
 * This class provides a skeletal implementation of the {@code Cache} interface to minimize the

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.ImmutableMap;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.Callable;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ExecutionException;

/**
 * This class provides a skeletal implementation of the {@code Cache} interface to minimize the

import static java.lang.Math.max;

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.MoreObjects;
import java.util.Objects;
import java.util.concurrent.Callable;
import org.jspecify.annotations.Nullable;

/**
 * Statistics about the performance of a {@link Cache}. Instances of this class are immutable.
 *
 * <p>Cache statistics are incremented according to the following rules:
 *
 * <ul>

import static java.lang.Math.max;

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.MoreObjects;
import java.util.Objects;
import java.util.concurrent.Callable;
import org.jspecify.annotations.Nullable;

/**
 * Statistics about the performance of a {@link Cache}. Instances of this class are immutable.
 *
 * <p>Cache statistics are incremented according to the following rules:
 *
 * <ul>

Aber wir wollen diesen vordefinierten Inhalt per Parameter festlegen können.

## Eine „aufrufbare“ Instanz { #a-callable-instance }

In Python gibt es eine Möglichkeit, eine Instanz einer Klasse <abbr title="Englisch „callable“">„aufrufbar“</abbr> zu machen.

Nicht die Klasse selbst (die bereits aufrufbar ist), sondern eine Instanz dieser Klasse.

Dazu deklarieren wir eine Methode `__call__`:

    ImmutableList.Builder<Future<?>> futures = ImmutableList.builder();
    for (int i = 0; i < threadCount; i++) {
      futures.add(
          executor.submit(
              new Callable<@Nullable Void>() {
                @Override
                public @Nullable Void call() throws Exception {
                  barrier.await();
                  Integer first = graph.nodes().iterator().next();

    CacheTesting.drainRecencyQueues(cache);
    ticker.advance(1, MILLISECONDS);
    assertThat(keySet).containsExactly(2, 3, 4, 5, 6, 7, 8, 9, 0);

    // get(K, Callable) doesn't stop 2 from expiring
    Integer unused = cache.get(2, Callables.returning(-2));
    CacheTesting.drainRecencyQueues(cache);
    ticker.advance(1, MILLISECONDS);
    assertThat(keySet).containsExactly(3, 4, 5, 6, 7, 8, 9, 0);