Simple fixes in single PRs do not require issues. 
  
        **Do you use the latest project version?**

  - type: input
    id: version
    attributes:
      label: Affected version
    validations:
      required: true

  - type: textarea
    id: message
    attributes:
      label: Bug description
    validations:

    }
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testAsMapRemoveImplementsSet() {
    List<K> keys = new ArrayList<>(multimap().keySet());
    for (K key : keys) {
      resetCollection();
      assertTrue(multimap().asMap().remove(key) instanceof Set);
    }
  }

  @CollectionSize.Require(SEVERAL)
  public void testEquals() {

    private val projectsToEnableNullaway = ConcurrentHashMap.newKeySet<String>()

    private fun ensureProjectNotSeen(projectPath: String) {
        require(projectPath !in projectsWithNullAwayEnabled)
        require(projectPath !in projectsWithUncheckedDeps)
        require(projectPath !in projectsToEnableNullaway)
    }

    fun addProjectWithNullawayEnabled(projectPath: String) {
        ensureProjectNotSeen(projectPath)

    extends AbstractMultimapTester<K, V, Multimap<K, V>> {

  @MapFeature.Require({SUPPORTS_PUT, SUPPORTS_REMOVE, ALLOWS_NULL_VALUES})
  public void testReplaceValuesWithNullValue() {
    List<V> values = asList(v0(), null, v3());
    multimap().replaceValues(k0(), values);
    assertGet(k0(), values);
  }

  @MapFeature.Require({SUPPORTS_PUT, SUPPORTS_REMOVE, ALLOWS_NULL_KEYS})
  public void testReplaceValuesWithNullKey() {

  }

  @CollectionFeature.Require(ALLOWS_NULL_QUERIES)
  public void testCount_nullAbsent() {
    assertEquals("multiset.count(null) didn't return 0", 0, getMultiset().count(null));
  }

  @CollectionFeature.Require(absent = ALLOWS_NULL_QUERIES)
  public void testCount_null_forbidden() {
    assertThrows(NullPointerException.class, () -> getMultiset().count(null));
  }

  @CollectionSize.Require(absent = ZERO)

    } catch (UnsupportedOperationException tolerated) {
    }
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testSetCount_oneToOne_addSupported() {
    assertOneToOne();
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testSetCount_oneToOne_removeSupported() {
    assertOneToOne();
  }

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
@NullMarked
public class MultisetIteratorTester<E extends @Nullable Object> extends AbstractMultisetTester<E> {
  @CollectionFeature.Require({SUPPORTS_ITERATOR_REMOVE, KNOWN_ORDER})
  public void testRemovingIteratorKnownOrder() {
    new IteratorTester<E>(
        4,
        MODIFIABLE,
        getSubjectGenerator().order(asList(e0(), e1(), e1(), e2())),

                  assertNull(v);
                  return null;
                }));
    expectUnchanged();
    assertEquals(getNumElements(), getMap().size());
  }

  @MapFeature.Require({SUPPORTS_PUT, SUPPORTS_REMOVE})
  @CollectionSize.Require(absent = ZERO)
  public void testCompute_presentToPresent() {
    assertEquals(
        "Map.compute(present, functionReturningValue) should return new value",
        v3(),
        getMap()

                  assertNull(v);
                  return null;
                }));
    expectUnchanged();
    assertEquals(getNumElements(), getMap().size());
  }

  @MapFeature.Require({SUPPORTS_PUT, SUPPORTS_REMOVE})
  @CollectionSize.Require(absent = ZERO)
  public void testCompute_presentToPresent() {
    assertEquals(
        "Map.compute(present, functionReturningValue) should return new value",
        v3(),
        getMap()

    new EqualsTester()
        .addEqualityGroup(multimap())
        .addEqualityGroup(getSubjectGenerator().create(targetEntries.toArray()))
        .testEquals();
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(ALLOWS_NULL_KEYS)
  public void testEqualsMultimapWithNullKey() {
    Multimap<K, V> original = multimap();
    initMultimapWithNullKey();
    Multimap<K, V> withNull = multimap();
    new EqualsTester()