* elements. The generated map is sorted by the natural ordering of the keys.
   *
   * <p>If the mapped keys contain duplicates, an {@code IllegalArgumentException} is thrown when
   * the collection operation is performed. (This differs from the {@code Collector} returned by
   * {@link Collectors#toMap(Function, Function)}, which throws an {@code IllegalStateException}.)
   *

public final class BigIntegerMath {
  /**
   * Returns the smallest power of two greater than or equal to {@code x}. This is equivalent to
   * {@code BigInteger.valueOf(2).pow(log2(x, CEILING))}.
   *
   * @throws IllegalArgumentException if {@code x <= 0}
   * @since 20.0
   */
  public static BigInteger ceilingPowerOfTwo(BigInteger x) {
    return BigInteger.ZERO.setBit(log2(x, CEILING));
  }

  /**

        .isEqualTo(new char[] {(char) 1, (char) 0, (char) 0});
  }

  public void testEnsureCapacity_fail() {
    assertThrows(IllegalArgumentException.class, () -> Chars.ensureCapacity(ARRAY1, -1, 1));
    assertThrows(IllegalArgumentException.class, () -> Chars.ensureCapacity(ARRAY1, 1, -1));
  }

  public void testJoin() {
    assertThat(Chars.join(",", EMPTY)).isEmpty();

    assertThrows(
        IllegalArgumentException.class,
        () -> Traverser.forTree(createDirectedGraph()).breadthFirst('a'));
  }

  @Test
  public void forTree_breadthFirstIterable_emptyGraph() {
    assertEqualCharNodes(
        Traverser.forTree(createDirectedGraph()).breadthFirst(charactersOf("")), "");
    assertThrows(
        IllegalArgumentException.class,

  public void testInvalidIntRange() {
    assertThrows(IllegalArgumentException.class, () -> ContiguousSet.closed(2, 1));
    assertThrows(IllegalArgumentException.class, () -> ContiguousSet.closedOpen(2, 1));
  }

  public void testInvalidLongRange() {
    assertThrows(IllegalArgumentException.class, () -> ContiguousSet.closed(2L, 1L));
    assertThrows(IllegalArgumentException.class, () -> ContiguousSet.closedOpen(2L, 1L));
  }

    public void test_valueOf_invalidName() {
        // Test valueOf with invalid name throws exception
        try {
            SsoResponseType.valueOf("INVALID");
            fail("Expected IllegalArgumentException");
        } catch (IllegalArgumentException e) {
            // Expected exception
            assertTrue(e.getMessage().contains("INVALID"));
        }
    }

    @Test
    public void test_valueOf_null() {

    assertThrows(IllegalArgumentException.class, () -> registry.unregister(new StringSubscriber()));

    StringSubscriber s1 = new StringSubscriber();
    registry.register(s1);
    assertThrows(IllegalArgumentException.class, () -> registry.unregister(new StringSubscriber()));

    registry.unregister(s1);

    assertThrows(IllegalArgumentException.class, () -> registry.unregister(s1));
  }

              e -> e instanceof ConcurrentModificationException)
          .put(ExecutionException.class, e -> e instanceof ExecutionException)
          .put(IllegalArgumentException.class, e -> e instanceof IllegalArgumentException)
          .put(IllegalStateException.class, e -> e instanceof IllegalStateException)
          .put(IndexOutOfBoundsException.class, e -> e instanceof IndexOutOfBoundsException)

              e -> e instanceof ConcurrentModificationException)
          .put(ExecutionException.class, e -> e instanceof ExecutionException)
          .put(IllegalArgumentException.class, e -> e instanceof IllegalArgumentException)
          .put(IllegalStateException.class, e -> e instanceof IllegalStateException)
          .put(IndexOutOfBoundsException.class, e -> e instanceof IndexOutOfBoundsException)

    network.addNode(N1);
    network.addNode(N2);
    IllegalArgumentException e =
        assertThrows(
            IllegalArgumentException.class,
            () -> networkForTest.edgesConnecting(N1, NODE_NOT_IN_GRAPH));
    assertNodeNotInGraphErrorMessage(e);
    e =
        assertThrows(
            IllegalArgumentException.class,
            () -> networkForTest.edgesConnecting(NODE_NOT_IN_GRAPH, N2));