}

      @Override
      @ParametricNullness
      public E next() {
        Map.Entry<E, Count> mapEntry = backingEntries.next();
        toRemove = mapEntry;
        return mapEntry.getKey();
      }

      @Override
      public void remove() {
        checkState(toRemove != null, "no calls to next() since the last call to remove()");
        size -= toRemove.getValue().getAndSet(0);

    @Test
    public void testEntrySet() throws Exception {
        Iterator<Map.Entry<String, String>> i = map.entrySet().iterator();
        assertThat(i.next().getKey(), is(nullValue()));
        assertThat(i.next().getKey(), is("1"));
        assertThat(i.next().getKey(), is("2"));
    }

    /**
     * Test method for {@link org.seasar.util.collection.ArrayIterator#remove()}
     * .
     */
    @Test

  public void testPutDuplicateValue() {
    List<Entry<K, V>> entries = copyToList(multimap().entries());

    for (Entry<K, V> entry : entries) {
      resetContainer();

      K k = entry.getKey();
      V v = entry.getValue();

      List<V> values = multimap().get(k);
      List<V> expectedValues = copyToList(values);

      assertTrue(multimap().put(k, v));
      expectedValues.add(v);

      }
      checkArgument(!containsValue(value), "value already present: %s", value);
      V oldValue = delegate.setValue(value);
      checkState(Objects.equals(value, get(getKey())), "entry no longer in map");
      updateInverseMap(getKey(), true, oldValue, value);
      return oldValue;
    }
  }

  Iterator<Entry<K, V>> entrySetIterator() {
    Iterator<Entry<K, V>> iterator = delegate.entrySet().iterator();

      for (Object element : elements) {
        @SuppressWarnings("unchecked")
        Entry<String, Integer> entry = (Entry<String, Integer>) element;
        multimap.put(entry.getKey(), entry.getValue());
      }
      return multimap.entries();
    }

    abstract Multimap<String, Integer> createMultimap();

    @Override
    @SuppressWarnings("unchecked")

It's acceptable for implementation classes to be written to fit into existing code, but new classes must not instantiate managed properties or implement getters manually.

This is preferred:

```groovy
public interface NewThing {
    Property<String> getSomeProperty()
}
```

This is acceptable:

```groovy
public interface NewThing {

  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testSetValue() {
    for (Entry<K, V> entry : getMap().entrySet()) {
      if (entry.getKey().equals(k0())) {
        assertEquals("entry.setValue() should return the old value", v0(), entry.setValue(v3()));
        break;
      }
    }
    expectReplacement(entry(k0(), v3()));
  }

  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testSetValue() {
    for (Entry<K, V> entry : getMap().entrySet()) {
      if (entry.getKey().equals(k0())) {
        assertEquals("entry.setValue() should return the old value", v0(), entry.setValue(v3()));
        break;
      }
    }
    expectReplacement(entry(k0(), v3()));
  }

  public void testPutDuplicateValue() {
    List<Entry<K, V>> entries = copyToList(multimap().entries());

    for (Entry<K, V> entry : entries) {
      resetContainer();

      K k = entry.getKey();
      V v = entry.getValue();

      List<V> values = multimap().get(k);
      List<V> expectedValues = copyToList(values);

      assertTrue(multimap().put(k, v));
      expectedValues.add(v);

public class MultimapKeySetTester<K, V> extends AbstractMultimapTester<K, V, Multimap<K, V>> {
  public void testKeySet() {
    for (Entry<K, V> entry : getSampleElements()) {
      assertTrue(multimap().keySet().contains(entry.getKey()));
    }
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(ALLOWS_NULL_KEYS)
  public void testKeySetContainsNullKeyPresent() {
    initMultimapWithNullKey();