Iterator<Entry<K, V>> iterator = multimap().entries().iterator();
    Entry<K, V> entry = iterator.next();
    K key = entry.getKey();
    V value = entry.getValue();
    multimap().removeAll(key);
    assertEquals(key, entry.getKey());
    assertEquals(value, entry.getValue());
  }

    assertThrows(
        IllegalArgumentException.class,
        () -> Stream.of(mapEntry("one", 1), mapEntry("one", 11)).collect(collector));
  }

  public void testToImmutableSortedMapMerging() {
    Collector<Entry<String, Integer>, ?, ImmutableSortedMap<String, Integer>> collector =
        toImmutableSortedMap(Entry::getKey, Entry::getValue, Integer::sum);

    assertThat(map.containsKey(refreshKey)).isFalse();

    // let computation complete
    letGetFinishSignal.countDown();
    getFinishedSignal.await();
    checkNothingLogged();

    // results should be visible
    assertThat(cache.size()).isEqualTo(2);
    assertThat(map.get(getKey)).isEqualTo(getKey + suffix);
    assertThat(map.get(refreshKey)).isEqualTo(refreshKey + suffix);

    Entry<String, Collection<Integer>> entry = iterator.next();
    assertThat(entry.getKey()).isNull();
    assertThat(entry.getValue()).containsExactly(7, 3, 1);
    entry = iterator.next();
    assertThat(entry.getKey()).isEqualTo("tree");
    assertThat(entry.getValue()).containsExactly(null, 0);
    entry = iterator.next();
    assertThat(entry.getKey()).isEqualTo("google");
    assertThat(entry.getValue()).containsExactly(6, 2);
  }

    public boolean equals(@Nullable Object object) {
      assertTrue(Thread.holdsLock(mutex));
      return super.equals(object);
    }

    @Override
    public K getKey() {
      assertTrue(Thread.holdsLock(mutex));
      return super.getKey();
    }

    @Override
    public V getValue() {
      assertTrue(Thread.holdsLock(mutex));
      return super.getValue();
    }

    @Override

        }

        private void putAll(Map<Object, Object> s, Map<Object, Object> t, Object excludeKey) {
            for (Map.Entry<Object, Object> e : t.entrySet()) {
                if (!e.getKey().equals(excludeKey)) {
                    s.put(e.getKey(), e.getValue());
                }
            }
        }

        @Override
        protected void mergePluginContainer_Plugins(

            for (Entry<Range<Integer>, Integer> entry : rangeMap.asMapOfRanges().entrySet()) {
              if (entry.getKey().isConnected(subRange)
                  && !entry.getKey().intersection(subRange).isEmpty()) {
                expectedBuilder.put(entry.getKey().intersection(subRange), entry.getValue());
              }
            }

          reverse(samples.e3()),
          reverse(samples.e4()));
    }

    private Entry<V, K> reverse(Entry<K, V> entry) {
      checkNotNull(entry);
      return mapEntry(entry.getValue(), entry.getKey());
    }

    @SuppressWarnings("unchecked")
    @Override
    public BiMap<V, K> create(Object... elements) {
      Entry<?, ?>[] entries = new Entry<?, ?>[elements.length];

                case 0:
                    return emptyMap();
                case 1:
                    Map.Entry<K, V> entry = map.entrySet().iterator().next();
                    return singletonMap(entry.getKey(), entry.getValue());
                default:
                    return new MapN<>(map);
            }
        }
    }

    @SuppressWarnings("unchecked")
    static <K, V> Map<K, V> emptyMap() {

    if (entry == null) {
      throw new NoSuchElementException();
    } else {
      return entry.getKey();
    }
  }

  @Override
  @ParametricNullness
  public K lastKey() {
    Entry<K, V> entry = lastEntry();
    if (entry == null) {
      throw new NoSuchElementException();
    } else {
      return entry.getKey();
    }
  }

  @Override
  public @Nullable Entry<K, V> lowerEntry(@ParametricNullness K key) {