}

  private void assertIteratorIsUnmodifiable(Iterator<?> iterator) {
    iterator.next();
    try {
      iterator.remove();
      fail();
    } catch (UnsupportedOperationException expected) {
    }
  }

  public void testSplitterIterableIsLazy_char() {
    assertSplitterIterableIsLazy(COMMA_SPLITTER);
  }

    }
    return new ConcatenatedHashFunction(hashFunctions);
  }

  /**
   * Used to randomize {@link #goodFastHash} instances, so that programs which persist anything
   * dependent on the hash codes they produce will fail sooner.
   */
  @SuppressWarnings("GoodTime") // reading system time without TimeSource
  static final int GOOD_FAST_HASH_SEED = (int) System.currentTimeMillis();

  /**
   * Returns a hash function implementing the <a

	id := mustGetRequestID(UTCNow())

	if len(id) != 16 {
		t.Fail()
	}

	var e rune
	for _, char := range id {
		e = char

		// Ensure that it is alphanumeric, in this case, between 0-9 and A-Z.
		isAlnum := ('0' <= e && e <= '9') || ('A' <= e && e <= 'Z')
		if !isAlnum {
			t.Fail()
		}
	}

    // Technically this listener is added after start() was called so it is a little gross, but it
    // is called within doStart() so we know that the service cannot terminate or fail concurrently
    // with adding this listener so it is impossible to miss an event that we are interested in.
    addListener(
        new Listener() {
          @Override
          public void terminated(State from) {

        }
    }

    @Nested
    @DisplayName("Downgrade Handling")
    class DowngradeHandlingTests {

        @Test
        @DisplayName("should fail with error when attempting downgrade from 4.1.0 to 4.0.0")
        void shouldFailWhenAttemptingDowngrade() throws Exception {
            String pomXml = """
                <?xml version="1.0" encoding="UTF-8"?>

// names of wrapped devices.
//
// There are currently no graph semantics implemented for registered custom
// devices, so executing tf.functions which contain operations placed on the
// custom devices will fail.
//
// `device_name` must not name an existing physical or custom device. It must
// follow the format:
//
//    /job:<name>/replica:<replica>/task:<task>/device:<type>:<device_num>
//

 *
 * This class is tolerant of some I/O errors. If files are missing from the filesystem, the
 * corresponding entries will be dropped from the cache. If an error occurs while writing a cache
 * value, the edit will fail silently. Callers should handle other problems by catching
 * `IOException` and responding appropriately.
 *
 * @constructor Create a cache which will reside in [directory]. This cache is lazily initialized on

            }

            // reactor failure modes
            if (t instanceof RuntimeException || !(t instanceof Exception)) {
                // fail fast on RuntimeExceptions, Errors and "other" Throwables
                // assume these are system errors and further build is meaningless
                buildContext.getReactorBuildStatus().halt();

    // it's shared to avoid using too much memory in tests
    long[] sharedArray = new long[arraysDim2];
    Arrays.fill(arrays, sharedArray);

    try {
      Longs.concat(arrays);
      fail();
    } catch (IllegalArgumentException expected) {
    }
  }

  private static void assertByteArrayEquals(byte[] expected, byte[] actual) {
    assertWithMessage(

        // CurlHelper not available → exception → caught internally → no throw
        try {
            helper.completeOperation("nonexistent_operation");
        } catch (final Exception e) {
            fail("completeOperation should not throw: " + e.getMessage());
        }
    }

    @Test
    public void test_completeOperation_doubleCall_safe() {