switch (edgesConnecting.size()) {
      case 0:
        return null;
      case 1:
        return edgesConnecting.iterator().next();
      default:
        throw new IllegalArgumentException(String.format(MULTIPLE_EDGES_CONNECTING, nodeU, nodeV));
    }
  }

  @Override
  public @Nullable E edgeConnectingOrNull(EndpointPair<N> endpoints) {
    validateEndpoints(endpoints);

      if (instance != null) {
        if (instance.getCause() == null) {
          instance.initCause(cause);
        }
        return instance;
      }
    }
    throw new IllegalArgumentException(
        "No appropriate constructor for exception of type "
            + exceptionClass
            + " in response to chained exception",
        cause);
  }

  RESTRICTS_VALUES,
  SUPPORTS_PUT,
  SUPPORTS_REMOVE,
  FAILS_FAST_ON_CONCURRENT_MODIFICATION,
  /**
   * Indicates that the constructor or factory method of a map, usually an immutable map, throws an
   * {@link IllegalArgumentException} when presented with duplicate keys instead of discarding all
   * but one.
   */
  REJECTS_DUPLICATES_AT_CREATION,

  GENERAL_PURPOSE(SUPPORTS_PUT, SUPPORTS_REMOVE);

  @Test
  fun requestHeaderValidationIsStrict() {
    assertFailsWith<IllegalArgumentException> {
      Request
        .Builder()
        .addHeader("a\tb", "Value")
    }
    assertFailsWith<IllegalArgumentException> {
      Request
        .Builder()
        .addHeader("Name", "c\u007fd")
    }
    assertFailsWith<IllegalArgumentException> {
      Request
        .Builder()

        info.updateFileId(testFileId);
        assertArrayEquals(testFileId, info.getFileId());

        // Test invalid file ID length
        assertThrows(IllegalArgumentException.class, () -> {
            info.updateFileId(new byte[8]);
        });
    }

    @Test
    public void testReconnectingState() {

        Exception cause = new IllegalArgumentException("Root cause");
        Exception exception = new RuntimeException("Wrapper exception", cause);

        monitorTarget.appendException(buf, exception);
        assertTrue(buf.toString().contains("Wrapper exception"));
        assertTrue(buf.toString().contains("Root cause"));
        assertTrue(buf.toString().contains("IllegalArgumentException"));
    }

     *
     * @param request the request containing the various data
     * @return a new {@link DependencyCoordinates} object
     *
     * @throws IllegalArgumentException if {@code request} is null or
     *         if {@code request.getSession()} is null or invalid
     */
    @Nonnull
    DependencyCoordinates create(@Nonnull DependencyCoordinatesFactoryRequest request);

    protected AbstractLifecycleMappingProvider(String[] pluginBindings) {
        requireNonNull(pluginBindings);
        final int len = pluginBindings.length;
        if (len < 2 || len % 2 != 0) {
            throw new IllegalArgumentException("Plugin bindings must have more than 0, even count of elements");
        }

        HashMap<String, LifecyclePhase> lifecyclePhaseBindings = new HashMap<>(len / 2);
        for (int i = 0; i < len; i = i + 2) {

  }

  /** Can't create the map if more than one value maps to the same key. */
  public void testUniqueIndexDuplicates() {
    IllegalArgumentException expected =
        assertThrows(
            IllegalArgumentException.class,
            () -> Maps.uniqueIndex(ImmutableSet.of("one", "uno"), Functions.constant(1)));
    assertThat(expected).hasMessageThat().contains("Multimaps.index");
  }

  protected abstract List<Class<? extends AbstractTester>> getTesters();

  private boolean matches(Test test) {
    Method method;
    try {
      method = extractMethod(test);
    } catch (IllegalArgumentException e) {
      logger.finer(Platform.format("%s: including by default: %s", test, e.getMessage()));
      return true;
    }
    if (suppressedTests.contains(method)) {