checkNotNull(safeChars); // eager for GWT.
    // Avoid any misunderstandings about the behavior of this escaper
    if (safeChars.matches(".*[0-9A-Za-z].*")) {
      throw new IllegalArgumentException(
          "Alphanumeric characters are always 'safe' and should not be explicitly specified");
    }
    safeChars += "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";

    void testMultipleCloseOnManagedResource() throws Exception {
        TestResource resource = new TestResource("multiclose");
        ResourceManager.ManagedResource<TestResource> managed = resourceManager.manage(resource);

        managed.close();
        assertTrue(resource.isClosed());

        // Second close should not throw
        assertDoesNotThrow(managed::close);
    }

    @Test

    void throwsSmbExceptionFromFilter() {
        SmbFilenameFilter filter = (dir, name) -> {
            throw new SmbException("boom");
        };

        SmbException ex = assertThrows(SmbException.class, () -> filter.accept(mockDir, "x"));
        assertEquals("boom", ex.getMessage(), "Exception message should be preserved");
        verifyNoInteractions(mockDir);
    }

    /**

              okayToRun.await();
            } catch (InterruptedException e) {
              Thread.currentThread().interrupt();
              throw new RuntimeException(e);
            }
            runCalled.getAndIncrement();
          }
        },
        directExecutor());
    Runnable execute =
        new Runnable() {
          @Override
          public void run() {
            list.execute();
          }

                    if (!Files.isDirectory(topDirectory)) {
                        throw new IllegalArgumentException("Directory " + topDirectory
                                + " extracted from the -f/--file command-line argument " + arg + " does not exist");
                    }
                } else {
                    throw new IllegalArgumentException(

  }

  @J2ktIncompatible
  @GwtIncompatible
  public void testAsAsyncCallable_exception() throws Exception {
    Exception expected = new IllegalArgumentException();
    Callable<String> callable =
        new Callable<String>() {
          @Override
          public String call() throws Exception {
            throw expected;
          }
        };

    AsyncCallable<String> asyncCallable =

            f.setAccessible(true);
            return f.get(target);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    // Helper: find field in class hierarchy
    private static Field findField(Class<?> clazz, String name) throws NoSuchFieldException {
        Class<?> current = clazz;
        while (current != null) {
            try {

   * given values. The returned range is {@linkplain BoundType#CLOSED closed} on both ends.
   *
   * @throws ClassCastException if the values are not mutually comparable
   * @throws NoSuchElementException if {@code values} is empty
   * @throws NullPointerException if any of {@code values} is null
   * @since 14.0
   */

     * @param replacement The replacement string.
     */
    public void add(final String target, final String replacement) {
        if (target == null || replacement == null) {
            throw new CrawlerSystemException("Target or replacement cannot be null.");
        }
        convertMap.put(target, replacement);
    }

    /**
     * Sets the conversion map.

  }

  @MapFeature.Require(absent = ALLOWS_NULL_KEY_QUERIES)
  public void testContains_nullNotContainedAndUnsupported() {
    expectNullKeyMissingWhenNullKeysUnsupported("containsKey(null) should return false or throw");
  }

  @MapFeature.Require(ALLOWS_NULL_KEYS)
  @CollectionSize.Require(absent = ZERO)
  public void testContains_nonNullWhenNullContained() {
    initMapWithNullKey();