expectContents(createArrayWithNullKey());
  }

  @MapFeature.Require(absent = ALLOWS_NULL_KEYS)
  @CollectionSize.Require(absent = ZERO)
  public void testCreateWithNullKeyUnsupported() {
    assertThrows(NullPointerException.class, () -> initMapWithNullKey());
  }

  @MapFeature.Require(ALLOWS_NULL_VALUES)
  @CollectionSize.Require(absent = ZERO)
  public void testCreateWithNullValueSupported() {
    initMapWithNullValue();

    }

    // Invalid: null is not allowed for valueOf
    @ParameterizedTest
    @NullSource
    @DisplayName("valueOf(null) throws NullPointerException")
    void valueOfRejectsNull(String input) {
        assertThrows(NullPointerException.class, () -> RequestParam.valueOf(input));
    }

    // Sanity: Enum.valueOf(Class, String) behaves identically to RequestParam.valueOf(String)
    @Test

   * throws a {@code ClassCastException} or {@code NullPointerException}.
   */
  static boolean safeContains(Collection<?> collection, @Nullable Object object) {
    checkNotNull(collection);
    try {
      return collection.contains(object);
    } catch (ClassCastException | NullPointerException e) {
      return false;
    }
  }

  /**

    }
    assertThrows(IndexOutOfBoundsException.class, () -> refArray.get(array.length));
  }

  public void testNewReferenceArray_withNullArray() throws Exception {
    assertThrows(NullPointerException.class, () -> Atomics.newReferenceArray(null));
  }

  public void testNullPointers() {
    NullPointerTester tester = new NullPointerTester();
    tester.testAllPublicConstructors(Atomics.class); // there aren't any

    assertThat(Strings.padStart("x", -1, '-')).isSameInstanceAs("x");
  }

  @SuppressWarnings("nullness") // test of a bogus call
  public void testPadStart_null() {
    assertThrows(NullPointerException.class, () -> Strings.padStart(null, 5, '0'));
  }

  public void testPadEnd_noPadding() {
    assertThat(Strings.padEnd("", 0, '-')).isSameInstanceAs("");

          .put(IndexOutOfBoundsException.class, e -> e instanceof IndexOutOfBoundsException)
          .put(NoSuchElementException.class, e -> e instanceof NoSuchElementException)
          .put(NullPointerException.class, e -> e instanceof NullPointerException)
          .put(NumberFormatException.class, e -> e instanceof NumberFormatException)
          .put(RuntimeException.class, e -> e instanceof RuntimeException)

          .put(IndexOutOfBoundsException.class, e -> e instanceof IndexOutOfBoundsException)
          .put(NoSuchElementException.class, e -> e instanceof NoSuchElementException)
          .put(NullPointerException.class, e -> e instanceof NullPointerException)
          .put(NumberFormatException.class, e -> e instanceof NumberFormatException)
          .put(RuntimeException.class, e -> e instanceof RuntimeException)

        NtlmHttpServletRequest request = new NtlmHttpServletRequest(mockRequest, null);

        // getRemoteUser() will throw NPE when trying to call getName() on null principal
        assertThrows(NullPointerException.class, () -> request.getRemoteUser());
        assertNull(request.getUserPrincipal());
        assertEquals("NTLM", request.getAuthType());
    }

    @Test

  @CollectionFeature.Require(absent = ALLOWS_NULL_VALUES)
  public void testAddAllAtIndex_nullUnsupported() {
    List<E> containsNull = singletonList(null);
    assertThrows(NullPointerException.class, () -> getList().addAll(0, containsNull));
    expectUnchanged();
    expectNullMissingWhenNullUnsupported(
        "Should not contain null after unsupported addAll(n, containsNull)");
  }

          .put(IndexOutOfBoundsException.class, e -> e instanceof IndexOutOfBoundsException)
          .put(NoSuchElementException.class, e -> e instanceof NoSuchElementException)
          .put(NullPointerException.class, e -> e instanceof NullPointerException)
          .put(NumberFormatException.class, e -> e instanceof NumberFormatException)
          .put(RuntimeException.class, e -> e instanceof RuntimeException)