}
      // The interface could be package-private or private.
      // filter out equals/hashCode/toString
      if (method.getName().equals("equals")
          && method.getParameterTypes().length == 1
          && method.getParameterTypes()[0] == Object.class) {
        continue;
      }
      if (method.getName().equals("hashCode") && method.getParameterTypes().length == 0) {
        continue;
      }

      assertErrorMessage(
          e,
          "the Object#hashCode ("
              + a.hashCode()
              + ") of "
              + a
              + " [group 1, item 1] must be equal to the Object#hashCode ("
              + b.hashCode()
              + ") of "
              + b);
      return;
    }
    fail("Should get invalid hashCode error");
  }

  public void testNullEqualityGroup() {

    @Override
    public V put(final K key, final V value) {
        int hashCode = 0;
        int index = 0;

        if (key != null) {
            hashCode = key.hashCode();
            index = (hashCode & 0x7FFFFFFF) % mapTable.length;
            for (Entry<K, V> e = mapTable[index]; e != null; e = e.next) {
                if (e.hashCode == hashCode && key.equals(e.key)) {
                    return swapValue(e, value);

        result = 31 * result + a.getGroupId().hashCode();
        result = 31 * result + a.getArtifactId().hashCode();
        result = 31 * result + a.getType().hashCode();
        if (a.getVersion() != null) {
            result = 31 * result + a.getVersion().hashCode();
        }
        result = 31 * result + (a.getClassifier() != null ? a.getClassifier().hashCode() : 0);

          checkNotNull(args[i]);
        }
      }
      return dummyReturnValue(interfaceType.resolveType(method.getGenericReturnType()));
    }

    @Override
    public int hashCode() {
      return identity().hashCode();
    }

    @Override
    public boolean equals(@Nullable Object obj) {
      if (obj instanceof DummyHandler) {
        DummyHandler that = (DummyHandler) obj;

    assertEquals(
        "multiset.entrySet() has incorrect hash code", 0, getMultiset().entrySet().hashCode());
  }

  @CollectionSize.Require(ONE)
  public void testEntrySet_hashCode_size1() {
    assertEquals(
        "multiset.entrySet() has incorrect hash code",
        1 ^ e0().hashCode(),
        getMultiset().entrySet().hashCode());
  }

  public void testEquals_yes() {
    assertTrue(

    assertEquals(
        "multiset.entrySet() has incorrect hash code", 0, getMultiset().entrySet().hashCode());
  }

  @CollectionSize.Require(ONE)
  public void testEntrySet_hashCode_size1() {
    assertEquals(
        "multiset.entrySet() has incorrect hash code",
        1 ^ e0().hashCode(),
        getMultiset().entrySet().hashCode());
  }

  public void testEquals_yes() {
    assertTrue(

        hash = hash * 31 + (plugin.isExtensions() ? 1 : 0);

        for (Dependency dependency : plugin.getDependencies()) {
            hash = hash * 31 + Objects.hashCode(dependency.getGroupId());
            hash = hash * 31 + Objects.hashCode(dependency.getArtifactId());
            hash = hash * 31 + Objects.hashCode(dependency.getVersion());
            hash = hash * 31 + Objects.hashCode(dependency.getType());

    assertEquals(
        "A Map's hashCode() should be the sum of those of its entries (where "
            + "a null element in an entry counts as having a hash of zero).",
        expectedHashCode,
        getMap().hashCode());
  }

  private static int hash(Entry<?, ?> e) {
    return (e.getKey() == null ? 0 : e.getKey().hashCode())
        ^ (e.getValue() == null ? 0 : e.getValue().hashCode());
  }

        this.version = version;
        this.hashCode = Objects.hash(groupId, artifactId, version);
    }

    public String getGroupId() {
        return groupId;
    }

    public String getArtifactId() {
        return artifactId;
    }

    public String getVersion() {
        return version;
    }

    @Override
    public int hashCode() {
        return hashCode;
    }

    @Override