long size();

  /**
   * Returns a current snapshot of this cache's cumulative statistics, or a set of default values if
   * the cache is not recording statistics. All statistics begin at zero and never decrease over the
   * lifetime of the cache.
   *
   * <p><b>Warning:</b> this cache may not be recording statistical data. For example, a cache

    }
  }

  @Test
  public void testPutNewValue() {
    assertThat(mapCache.put("key", "value")).isNull();
    assertThat(mapCache.get("key")).isEqualTo("value"); // ensure key/value is cached
    assertThat(mapCache.put("key", "new value")).isEqualTo("value");
    assertThat(mapCache.get("key")).isEqualTo("new value");
  }

  @Test
  public void testRemoveEqualKeyWithDifferentReference() {

   * LoadingCache#getAll}.
   *
   * <p>If the returned map doesn't contain all requested {@code keys} then the entries it does
   * contain will be cached, but {@code getAll} will throw an exception. If the returned map
   * contains extra keys not present in {@code keys} then all returned entries will be cached, but
   * only the entries for {@code keys} will be returned from {@code getAll}.
   *

    /**
     * Registers the specified cache record for usage with the given project. Integrators can use the information
     * collected from this method in combination with a custom cache implementation to dispose unused records from the
     * cache.
     *
     * @param project The project that employs the plugin realm, must not be {@code null}.
     * @param record The cache record being used for the project, must not be {@code null}.

/**
 * 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>
 *   <li>When a cache lookup encounters an existing cache entry {@code hitCount} is incremented.
 *   <li>When a cache lookup first encounters a missing cache entry, a new entry is loaded.
 *       <ul>

    firstException = expected;
    // Second time should also fail, with a cached causal chain.
    expected = assertThrows(PotentialDeadlockException.class, () -> lockA.lock());
    checkMessage(expected, "LockB -> LockA", "LockA -> LockB");
    // The causal chain should be cached.
    assertSame(firstException.getCause(), expected.getCause());
    // lockA should work after lockB is released.

/**
 * 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>
 *   <li>When a cache lookup encounters an existing cache entry {@code hitCount} is incremented.
 *   <li>When a cache lookup first encounters a missing cache entry, a new entry is loaded.
 *       <ul>

    assertEquals(MAX_SIZE, cache.size());
    CacheTesting.processPendingNotifications(cache);
    assertEquals(MAX_SIZE, removalListener.getCount());
    CacheTesting.checkValidState(cache);
  }

  /**
   * With an unlimited-size cache with maxWeight of 0, entries weighing 0 should still be cached.
   * Entries with positive weight should not be cached (nor dump existing cache).
   */

  }

  public void testGetAllPresent_empty() {
    Cache<Object, Object> cache =
        new AbstractCache<Object, Object>() {
          @Override
          public @Nullable Object getIfPresent(Object key) {
            return null;
          }
        };

    assertEquals(ImmutableMap.of(), cache.getAllPresent(ImmutableList.of(new Object())));
  }

        // TODO: Remove the following code when maven-compat is gone
        // This code is here to ensure maven-compat's EmptyLifecycleExecutor keeps on working.
        if (lookup == null) {
            return customLifecycles != null ? customLifecycles : new HashMap<>();
        }

        // Lifecycles cannot be cached as extensions might add custom lifecycles later in the execution.
        try {