- [ ] Provide unit tests (under `<subproject>/src/test`) to verify logic.
- [ ] Update User Guide, DSL Reference, and Javadoc for public-facing changes.
- [ ] Ensure that tests pass sanity check: `./gradlew sanityCheck`.
- [ ] Ensure that tests pass locally: `./gradlew <changed-subproject>:quickTest`.

### Reviewing cheatsheet

    return getMultiset().setCount(element, getMultiset().count(element), count);
  }

  private void assertSetCountNegativeOldCount() {
    try {
      getMultiset().setCount(e3(), -1, 1);
      fail("calling setCount() with a negative oldCount should throw IllegalArgumentException");
    } catch (IllegalArgumentException expected) {
    }
  }

  // Negative oldCount.

  @CollectionFeature.Require(SUPPORTS_ADD)

  public static boolean equal(@Nullable Object a, @Nullable Object b) {
    return java.util.Objects.equals(a, b);
  }

  /**
   * Generates a hash code for multiple values. The hash code is generated by calling {@link
   * Arrays#hashCode(Object[])}. Note that array arguments to this method, with the exception of a
   * single Object array, do not get any special handling; their hash codes are based on identity
   * and not contents.

@Tag("Slowish")
class MultipartReaderTest {
  @Test fun `parse multipart`() {
    val multipart =
      """
      |--simple boundary
      |Content-Type: text/plain; charset=utf-8
      |Content-ID: abc
      |
      |abcd
      |efgh
      |--simple boundary
      |Content-Type: text/plain; charset=utf-8
      |Content-ID: ijk
      |
      |ijkl
      |mnop
      |
      |--simple boundary--
      """.trimMargin()

  }

  public void testAddAfterRun() throws Exception {
    // Run the previous test
    testRunOnPopulatedList();

    // If it passed, then verify an Add will be executed without calling run
    CountDownLatch countDownLatch = new CountDownLatch(1);
    list.add(new MockRunnable(countDownLatch), newCachedThreadPool());
    assertTrue(countDownLatch.await(1L, SECONDS));
  }

  public static boolean equal(@Nullable Object a, @Nullable Object b) {
    return java.util.Objects.equals(a, b);
  }

  /**
   * Generates a hash code for multiple values. The hash code is generated by calling {@link
   * Arrays#hashCode(Object[])}. Note that array arguments to this method, with the exception of a
   * single Object array, do not get any special handling; their hash codes are based on identity
   * and not contents.

     * Null pointer scenario – calls on a null reference should raise
     * {@link NullPointerException}. This test is defensive; in real code it
     * would likely be handled elsewhere.
     */
    @Test
    @DisplayName("calling getters on null reference throws NPE")
    void testNullReference() {
        AllocInfo nullRef = null;
        assertThrows(NullPointerException.class, () -> nullRef.getCapacity());

   * RuntimeException}, {@link Error}, or {@code declaredType}.
   *
   * <p><b>Discouraged</b> in favor of calling {@link #throwIfInstanceOf} and {@link
   * #throwIfUnchecked}.
   *
   * @param throwable the Throwable to possibly propagate
   * @param declaredType the single checked exception type declared by the calling method
   * @deprecated Use a combination of {@link #throwIfInstanceOf} and {@link #throwIfUnchecked},

    assertFalse(
        "multiset.entrySet() contains a non-entry", getMultiset().entrySet().contains(e0()));
  }

  public void testEntrySet_twice() {
    assertEquals(
        "calling multiset.entrySet() twice returned unequal sets",
        getMultiset().entrySet(),
        getMultiset().entrySet());
  }

  @CollectionSize.Require(ZERO)
  public void testEntrySet_hashCode_size0() {

    assertFalse(
        "multiset.entrySet() contains a non-entry", getMultiset().entrySet().contains(e0()));
  }

  public void testEntrySet_twice() {
    assertEquals(
        "calling multiset.entrySet() twice returned unequal sets",
        getMultiset().entrySet(),
        getMultiset().entrySet());
  }

  @CollectionSize.Require(ZERO)
  public void testEntrySet_hashCode_size0() {