}

  @MapFeature.Require(absent = ALLOWS_NULL_KEY_QUERIES)
  public void testGet_nullNotContainedAndUnsupported() {
    try {
      assertNull("get(null) should return null or throw", get(null));
    } catch (NullPointerException tolerated) {
    }
  }

  @MapFeature.Require(ALLOWS_NULL_KEYS)
  @CollectionSize.Require(absent = ZERO)
  public void testGet_nonNullWhenNullContained() {
    initMapWithNullKey();

  public void testFind_nullNotContainedAndUnsupported() {
    try {
      assertEquals(getMethodName() + "(nullNotPresent) should return -1 or throw", -1, find(null));
    } catch (NullPointerException tolerated) {
    }
  }

  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
  @CollectionSize.Require(absent = ZERO)
  public void testFind_nonNullWhenNullContained() {
    initCollectionWithNullElement();

   * set is serializable.
   *
   * @param elements the elements that the set should contain
   * @return a new thread-safe set containing those elements (minus duplicates)
   * @throws NullPointerException if {@code elements} or any of its contents is null
   * @since 15.0
   */
  public static <E> Set<E> newConcurrentHashSet(Iterable<? extends E> elements) {
    Set<E> set = newConcurrentHashSet();

        try {
            final boolean result = validator.isValid("test", null);
            assertNotNull("isValid should return a boolean result", Boolean.valueOf(result));
        } catch (final NullPointerException e) {
            // This is expected if the implementation requires a non-null context
            assertTrue("NPE is acceptable for null context in this implementation", true);
        }
    }

   * java.util.List} or some other collection that preserves the order in which the exceptions got
   * added.
   *
   * @throws NullPointerException if {@code exceptions} is null
   * @throws IllegalArgumentException if {@code exceptions} is empty
   */
  static RuntimeException create(Collection<? extends Throwable> exceptions) {
    if (exceptions.size() == 0) {

   * This reduces the expense of habitually making defensive copies at API boundaries. However, the
   * precise conditions for skipping the copy operation are undefined.
   *
   * @throws NullPointerException if any of {@code elements} is null
   * @since 7.0 (source-compatible since 2.0)
   */
  // This the best we could do to get copyOfEnumSet to compile in the mainline.

    public void test_encodeUrl_empty_and_null() {
        assertEquals("", DocumentUtil.encodeUrl(""));
        try {
            DocumentUtil.encodeUrl(null);
            fail("Should throw NullPointerException");
        } catch (NullPointerException e) {
            // Expected
        }
    }

    public void test_encodeUrl_unicode() {
        assertEquals("%3F", DocumentUtil.encodeUrl("あ"));

  }

  @CollectionFeature.Require(absent = ALLOWS_NULL_QUERIES)
  public void testContainsAll_nullNotAllowed() {
    try {
      assertFalse(collection.containsAll(MinimalCollection.of((E) null)));
    } catch (NullPointerException tolerated) {
    }
  }

  @CollectionFeature.Require(ALLOWS_NULL_QUERIES)
  public void testContainsAll_nullAllowed() {
    assertFalse(collection.containsAll(MinimalCollection.of((E) null)));
  }

    // URL escapers should throw null pointer exceptions for null input
    try {
      e.escape((String) null);
      fail("Escaping null string should throw exception");
    } catch (NullPointerException x) {
      // pass
    }

    // All URL escapers should leave 0-9, A-Z, a-z unescaped
    assertUnescaped(e, 'a');
    assertUnescaped(e, 'z');
    assertUnescaped(e, 'A');
    assertUnescaped(e, 'Z');

    assertFalse(multimap().containsKey(null));
  }

  @MapFeature.Require(absent = ALLOWS_NULL_KEY_QUERIES)
  public void testContainsKeyNullDisallowed() {
    assertThrows(NullPointerException.class, () -> multimap().containsKey(null));
  }