Map<String, @Nullable Integer> map = new HashMap<>();
    map.put("One", 1);
    map.put("Three", 3);
    map.put("Null", null);
    Function<String, @Nullable Integer> function = Functions.forMap(map);

    assertEquals(1, function.apply("One").intValue());
    assertEquals(3, function.apply("Three").intValue());
    assertThat(function.apply("Null")).isNull();

   * return the value but instead throw an exception.
   */
  private var trailers: Headers? = null

  override val isResponseComplete: Boolean
    get() = state == STATE_CLOSED

  override fun createRequestBody(
    request: Request,
    contentLength: Long,
  ): Sink =
    when {
      request.body?.isDuplex() == true -> throw ProtocolException(

          "TLS_NULL_WITH_NULL_NULL", "SSL_NULL_WITH_NULL_NULL" -> {
            throw IOException("cipherSuite == $cipherSuiteString")
          }

          else -> CipherSuite.forJavaName(cipherSuiteString)
        }

      val tlsVersionString = checkNotNull(protocol) { "tlsVersion == null" }
      if ("NONE" == tlsVersionString) throw IOException("tlsVersion == NONE")

            for (Artifact a : artifacts) {
                if (parents.contains(a.getDependencyConflictId())) {
                    a.setDependencyTrail(getDependencyTrail());

                    throw new CyclicDependencyException("A dependency has introduced a cycle", a);
                }

                children.add(new ResolutionNode(a, remoteRepositories, this));
            }

    Comparable<?> endpoint() {
      throw new IllegalStateException("range unbounded on this side");
    }

    @Override
    boolean isLessThan(Comparable<?> value) {
      return true;
    }

    @Override
    BoundType typeAsLowerBound() {
      throw new IllegalStateException();
    }

    @Override
    BoundType typeAsUpperBound() {

        // You can't say "assuming String is Integer".
        // And we don't support "assuming String is T"; user has to say "assuming T is String".
        throw new IllegalArgumentException("No type mapping from " + fromClass + " to " + to);
      }
    }.visit(from);
  }

  /**
   * Resolves all type variables in {@code type} and all downstream types and returns a

        def table = getSection(title).table[0]
        if (!table) {
            throw new RuntimeException("Section '$title' does not contain a <table> element.")
        }
        if (!table.thead[0]) {
            throw new RuntimeException("Table '$title' does not contain a <thead> element.")
        }
        if (!table.thead[0].tr[0]) {
            throw new RuntimeException("Table '$title' does not contain a <thead>/<tr> element.")

  final UnmodifiableIterator<Cell<R, C, V>> cellIterator() {
    throw new AssertionError("should never be called");
  }

  @Override
  public ImmutableCollection<V> values() {
    return (ImmutableCollection<V>) super.values();
  }

  @Override
  abstract ImmutableCollection<V> createValues();

  @Override
  final Iterator<V> valuesIterator() {
    throw new AssertionError("should never be called");
  }

            if (cells.size() != header.size()) {
                throw new RuntimeException(String.format("Expected %s <td> elements in <tr>, found: %s", header.size(), tr));
            }
            String propName = cells.get(0).getTextContent().trim();
            PropertyMetaData property = classDoc.getClassMetaData().findProperty(propName);
            if (property == null) {

    registry.register(o1);

    Iterator<Subscriber> three = registry.getSubscribers("");
    assertEquals(s1, one.next().target);
    assertFalse(one.hasNext());

    assertEquals(s1, three.next().target);
    assertEquals(s2, three.next().target);
    assertEquals(o1, three.next().target);
    assertFalse(three.hasNext());

    three = registry.getSubscribers("");

    registry.unregister(s2);