@Override
    public void finalizeReferent() {
      finalizeReferentCalled = true;
    }
  }

  /**
   * Keeps a weak reference to the underlying reference queue. When this reference is cleared, we
   * know that the background thread has stopped and released its strong reference.
   */
  private WeakReference<ReferenceQueue<Object>> queueReference;

  @Test
  public void testThatFinalizerStops() {
    weaklyReferenceQueue();

    @Override
    public void finalizeReferent() {
      finalizeReferentCalled = true;
    }
  }

  /**
   * Keeps a weak reference to the underlying reference queue. When this reference is cleared, we
   * know that the background thread has stopped and released its strong reference.
   */
  private WeakReference<ReferenceQueue<Object>> queueReference;

  @Test
  public void testThatFinalizerStops() {
    weaklyReferenceQueue();

        super.init(config);

        final Properties p = new Properties();
        p.putAll(System.getProperties());
        /*
         * Set jcifs properties we know we want; soTimeout and cachePolicy to 10min.
         */
        p.setProperty("jcifs.smb.client.soTimeout", "300000");
        p.setProperty("jcifs.netbios.cachePolicy", "600");

    for (Striped<?> striped : allImplementations()) {
      new NullPointerTester().testAllPublicInstanceMethods(striped);
    }
  }

  public void testSizes() {
    // not bothering testing all variations, since we know they share implementations
    assertTrue(Striped.lock(100).size() >= 100);
    assertTrue(Striped.lock(256).size() == 256);
    assertTrue(Striped.lazyWeakLock(100).size() >= 100);

    for (Striped<?> striped : allImplementations()) {
      new NullPointerTester().testAllPublicInstanceMethods(striped);
    }
  }

  public void testSizes() {
    // not bothering testing all variations, since we know they share implementations
    assertTrue(Striped.lock(100).size() >= 100);
    assertTrue(Striped.lock(256).size() == 256);
    assertTrue(Striped.lazyWeakLock(100).size() >= 100);

  }

  public void testBuilder_presize_negative() {
    assertThrows(IllegalArgumentException.class, () -> ImmutableDoubleArray.builder(-1));
  }

  /**
   * If there's a bug in builder growth, we wouldn't know how to expose it. So, brute force the hell
   * out of it for a while and see what happens.
   */
  public void testBuilder_bruteForce() {
    for (int i = 0; i < reduceIterationsIfGwt(100); i++) {

* And many other things

## Conclusion { #conclusion }

If you read and understood all this, now **you know much more** about virtual environments than many developers out there. 🤓

    assertSize(0);
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    assertSize(3);
  }

  public void testEquals() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    // We know that we have only added non-null Characters.
    Table<String, Integer, Character> hashCopy =
        HashBasedTable.create((Table<String, Integer, ? extends Character>) table);

     * The priority of this URL relative to other URLs on your site. Valid
     * values range from 0.0 to 1.0. This value does not affect how your pages
     * are compared to pages on other sites—it only lets the search engines know
     * which pages you deem most important for the crawlers.
     *
     * The default priority of a page is 0.5.
     *
     * Please note that the priority you assign to a page is not likely to

    By having the type as `int | None`, SQLModel will know that this column should be an `INTEGER` in the SQL database and that it should be `NULLABLE`.

* `Field(index=True)` tells SQLModel that it should create a **SQL index** for this column, that would allow faster lookups in the database when reading data filtered by this column.