try {
      Maps.uniqueIndex((List<String>) listWithNull, Functions.constant(1));
      fail();
    } catch (NullPointerException expected) {
    }
  }

  /** Null keys aren't allowed either. */
  public void testUniqueIndexNullKey() {
    List<String> oneStringList = Lists.newArrayList("foo");
    try {
      Maps.uniqueIndex(oneStringList, Functions.constant(null));
      fail();

            i3, // Integer subscribers are dispatched to first.
            s1,
            s2, // Though each integer subscriber dispatches to all string subscribers,
            s1,
            s2, // those string subscribers aren't actually dispatched to until all integer
            s1,
            s2 // subscribers have finished.
            )
        .inOrder();
  }

  public void testLegacyAsyncDispatcher() {

  }

  // Null support depends on the underlying table and function.
  @J2ktIncompatible
  @GwtIncompatible // NullPointerTester
  @Override
  public void testNullPointerInstance() {}

  // put() and putAll() aren't supported.
  @Override
  public void testPut() {
    try {
      table.put("foo", 1, 'a');
      fail("Expected UnsupportedOperationException");
    } catch (UnsupportedOperationException expected) {
    }

    } finally {
      Thread.currentThread().setContextClassLoader(oldContextLoader);
    }
  }

  @AndroidIncompatible // .class files aren't available
  public void testNulls() {
    new NullPointerTester()
        .setDefault(URL.class, classfile(ResourcesTest.class))
        .testAllPublicStaticMethods(Resources.class);
  }

        .containsExactly(0, 1, 3, 6, 10, 15, 21)
        .inOrder();
  }

  public void testCopyOf_array_empty() {
    /*
     * We don't guarantee the same-as property, so we aren't obligated to test it. However, it's
     * useful in testing - when two things are the same then one can't have bugs the other doesn't.
     */

   */
  protected final <T> void setDistinctValues(Class<T> type, T value1, T value2) {
    tester.setDistinctValues(type, value1, value2);
  }

  /** Specifies that classes that satisfy the given predicate aren't tested for sanity. */
  protected final void ignoreClasses(Predicate<? super Class<?>> condition) {
    this.classFilter = and(this.classFilter, not(condition));
  }

  private static AssertionFailedError sanityError(

        return new RegularImmutableAsList<>(this, toArray());
    }
  }

  /**
   * Returns {@code true} if this immutable collection's implementation contains references to
   * user-created objects that aren't accessible via this collection's methods. This is generally
   * used to determine whether {@code copyOf} implementations should make an explicit copy to avoid
   * memory leaks.
   */
  abstract boolean isPartialView();

    return isEmpty() ? ImmutableList.of() : ImmutableList.asImmutableList(toArray());
  }

  /**
   * Returns {@code true} if this immutable collection's implementation contains references to
   * user-created objects that aren't accessible via this collection's methods. This is generally
   * used to determine whether {@code copyOf} implementations should make an explicit copy to avoid
   * memory leaks.
   */
  abstract boolean isPartialView();

       * valid value. That's the best we can do, short of holding a reference to the most recently
       * seen value. And while we *could* do that, we aren't required to: Map.Entry explicitly says
       * that behavior is undefined when the backing map is modified through another API. (It even

  }

  boolean usesValueReferences() {
    return valueStrength != Strength.STRONG;
  }

  enum Strength {
    /*
     * TODO(kevinb): If we strongly reference the value and aren't loading, we needn't wrap the
     * value. This could save ~8 bytes per entry.
     */

    STRONG {
      @Override
      <K, V> ValueReference<K, V> referenceValue(