public void testPutAll_nullKeyUnsupported() {
    assertThrows(NullPointerException.class, () -> putAll(containsNullKey));
    expectUnchanged();
    expectNullKeyMissingWhenNullKeysUnsupported(
        "Should not contain null key after unsupported putAll(containsNullKey)");
  }

  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_VALUES})
  public void testPutAll_nullValueSupported() {
    putAll(containsNullValue);

     * lu/GJQZoU9lDrCPeUcQ28tzOWw==
     * -----END PRIVATE KEY-----
     * ```
     *
     * The string should contain exactly one certificate and one private key in [PKCS #8][rfc_5208]
     * format. It should not contain any other PEM-encoded blocks, but it may contain other text
     * which will be ignored.
     *
     * Encode a held certificate into this format by concatenating the results of

  @CollectionSize.Require(absent = ZERO)
  public void testRemove_present() {
    getSet().remove(e0());
    assertFalse(
        "After remove(present) a set should not contain the removed element.",
        getSet().contains(e0()));
  }

  @CollectionSize.Require(absent = ZERO)
  public void testRemove_present() {
    getSet().remove(e0());
    assertFalse(
        "After remove(present) a set should not contain the removed element.",
        getSet().contains(e0()));
  }

        /*
         * standardToArray returns `@Nullable Object[]` rather than `Object[]` but only because it
         * can be used with collections that may contain null. This collection is a collection of
         * non-null Entry objects (Entry objects that might contain null values but are not
         * themselves null), so we can treat it as a plain `Object[]`.
         */
        @SuppressWarnings("nullness")

   *
   * <p><b>Java 8+ users:</b> use {@link Long#parseUnsignedLong(String)} instead.
   *
   * @throws NumberFormatException if the string does not contain a valid unsigned {@code long}
   *     value
   * @throws NullPointerException if {@code string} is null (in contrast to {@link
   *     Long#parseLong(String)})
   */
  @CanIgnoreReturnValue

  public void testAddAtIndex_nullUnsupported() {
    assertThrows(NullPointerException.class, () -> getList().add(0, null));
    expectUnchanged();
    expectNullMissingWhenNullUnsupported("Should not contain null after unsupported add(n, null)");
  }

  @ListFeature.Require(SUPPORTS_ADD_WITH_INDEX)
  public void testAddAtIndex_negative() {
    assertThrows(IndexOutOfBoundsException.class, () -> getList().add(-1, e3()));

    assertTrue(
        "multiset.elementSet().contains(present) returned false",
        getMultiset().elementSet().contains(e0()));
  }

  @CollectionSize.Require(absent = ZERO)
  public void testEntrySet_contains() {
    assertTrue(
        "multiset.entrySet() didn't contain [present, 1]",
        getMultiset().entrySet().contains(Multisets.immutableEntry(e0(), 1)));
  }

    assertTrue(
        "multiset.elementSet().contains(present) returned false",
        getMultiset().elementSet().contains(e0()));
  }

  @CollectionSize.Require(absent = ZERO)
  public void testEntrySet_contains() {
    assertTrue(
        "multiset.entrySet() didn't contain [present, 1]",
        getMultiset().entrySet().contains(Multisets.immutableEntry(e0(), 1)));
  }

  // expectedHashCodes must contain at least one hash code with 4 bytes
  public void testFromInt() {
    for (ExpectedHashCode expected : expectedHashCodes) {
      if (expected.bytes.length == 4) {
        HashCode fromInt = HashCode.fromInt(expected.asInt);
        assertExpectedHashCode(expected, fromInt);
      }
    }
  }

  // expectedHashCodes must contain at least one hash code with 8 bytes