assertFalse(getMap().entrySet().iterator().hasNext());
  }

  @MapFeature.Require({FAILS_FAST_ON_CONCURRENT_MODIFICATION, SUPPORTS_REMOVE})
  @CollectionSize.Require(SEVERAL)
  public void testClearConcurrentWithEntrySetIteration() {
    assertThrows(
        ConcurrentModificationException.class,
        () -> {
          Iterator<Entry<K, V>> iterator = getMap().entrySet().iterator();
          getMap().clear();

            }
            values.add(value);
            key = connection.getHeaderFieldKey(i);
            value = connection.getHeaderField(i);
        }
        final Iterator entries = map.entrySet().iterator();
        while (entries.hasNext()) {
            final Map.Entry entry = (Map.Entry) entries.next();
            entry.setValue(Collections.unmodifiableList((List) entry.getValue()));
        }

    } catch (RuntimeException tolerated) {
      // GWT's TreeMap.entrySet().removeAll(null) doesn't throws NPE.
    }
  }

  @Override
  public void testEntrySetRetainAllNullFromEmpty() {
    try {
      super.testEntrySetRetainAllNullFromEmpty();
    } catch (RuntimeException tolerated) {
      // GWT's TreeMap.entrySet().retainAll(null) doesn't throws NPE.
    }
  }

  @Override

    }

    public static <K, T extends Map<K, Artifact>> T copyArtifacts(Map<K, ? extends Artifact> from, T to) {
        if (from != null) {
            for (Map.Entry<K, ? extends Artifact> entry : from.entrySet()) {
                to.put(entry.getKey(), ArtifactUtils.copyArtifact(entry.getValue()));
            }
        }

        return to;
    }

    private static <T> List<T> copyList(List<T> original) {

    List<Entry<V, K>> reversedEntries = new ArrayList<>();
    for (Entry<K, V> entry : expected) {
      reversedEntries.add(reverseEntry(entry));
    }
    assertEqualIgnoringOrder(getMap().inverse().entrySet(), reversedEntries);

    for (Entry<K, V> entry : expected) {
      assertEquals(
          "Wrong key for value " + entry.getValue(),
          entry.getKey(),
          getMap().inverse().get(entry.getValue()));

    assertEquals(
        "multiset.count() should return the value passed to setCount()",
        count,
        getMultiset().count(element));

    int size = 0;
    for (Multiset.Entry<E> entry : getMultiset().entrySet()) {
      size += entry.getCount();
    }
    assertEquals(
        "multiset.size() should be the sum of the counts of all entries",
        size,
        getMultiset().size());
  }

        return CollectSpliterators.map(submap.entrySet().spliterator(), AsMap.this::wrapEntry);
      }

      // The following methods are included for performance.

      @Override
      public boolean contains(@Nullable Object o) {
        return Collections2.safeContains(submap.entrySet(), o);
      }

      @Override
      public boolean remove(@Nullable Object o) {

        try {
            // feature
            for (final Map.Entry<String, String> entry : featureMap.entrySet()) {
                parser.setFeature(entry.getKey(), "true".equalsIgnoreCase(entry.getValue()));
            }

            // property
            for (final Map.Entry<String, String> entry : propertyMap.entrySet()) {
                parser.setProperty(entry.getKey(), entry.getValue());
            }

  @CollectionSize.Require(SEVERAL)
  public void testPollFirst() {
    assertEquals(a, navigableMap.pollFirstEntry());
    assertEquals(entries.subList(1, entries.size()), copyToList(navigableMap.entrySet()));
  }

  @MapFeature.Require(absent = SUPPORTS_REMOVE)
  public void testPollFirstUnsupported() {
    assertThrows(UnsupportedOperationException.class, () -> navigableMap.pollFirstEntry());
  }

  @CollectionSize.Require(SEVERAL)
  public void testPollFirst() {
    assertEquals(a, navigableMap.pollFirstEntry());
    assertEquals(entries.subList(1, entries.size()), copyToList(navigableMap.entrySet()));
  }

  @MapFeature.Require(absent = SUPPORTS_REMOVE)
  public void testPollFirstUnsupported() {
    assertThrows(UnsupportedOperationException.class, () -> navigableMap.pollFirstEntry());
  }