* @throws IllegalArgumentException if the endpoints are unordered and the network is directed
   * @since 27.1
   */
  Set<E> edgesConnecting(EndpointPair<N> endpoints);

  /**
   * Returns the single edge that directly connects {@code nodeU} to {@code nodeV}, if one is
   * present, or {@code Optional.empty()} if no such edge exists.
   *

/**
 * A generic JUnit test which tests {@code spliterator} operations on a collection. Can't be invoked
 * directly; please see {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.

        errorResponse.message(testMessage);
        errorResponse.status(Status.BAD_REQUEST);
        ApiResult result = errorResponse.result();

        assertNotNull(result);
        // Cannot directly access protected fields, just verify the result is not null
    }

    // Test configuration for JSON response
    public void test_configurationSettings() {
        ComponentUtil.setFessConfig(new FessConfig.SimpleImpl() {

/**
 * A generic JUnit test which tests {@code add(int, Object)} operations on a list. Can't be invoked
 * directly; please see {@link com.google.common.collect.testing.ListTestSuiteBuilder}.
 *
 * @author Chris Povirk
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.

 * method) of a map. Can't be invoked directly; please see {@link
 * com.google.common.collect.testing.MapTestSuiteBuilder}.
 *
 * @author Chris Povirk
 * @author Kevin Bourrillion
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")

 * method) of a collection. Can't be invoked directly; please see {@link
 * com.google.common.collect.testing.CollectionTestSuiteBuilder}.
 *
 * @author Chris Povirk
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.

        assertTrue(filename.contains("/"));
    }

    // Test getImageFilename with docid - use the String version directly
    public void test_getImageFilename_withDocId() {
        String docid = "1234567890abcdef";
        // Call the String version directly
        String filename = thumbnailManager.getImageFilename(docid);
        assertNotNull(filename);
        assertTrue(filename.endsWith(".png"));

  @SuppressWarnings("ThrowIfUncheckedKnownUnchecked")
  public void testThrowIfUnchecked_unchecked() {
    assertThrows(
        SomeUncheckedException.class, () -> throwIfUnchecked(new SomeUncheckedException()));
  }

  // We're testing that the method is in fact equivalent to throwing the exception directly.
  @SuppressWarnings("ThrowIfUncheckedKnownUnchecked")

/**
 * A generic JUnit test which tests {@code listIterator} operations on a list. Can't be invoked
 * directly; please see {@link com.google.common.collect.testing.ListTestSuiteBuilder}.
 *
 * @author Chris Povirk
 * @author Kevin Bourrillion
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")

/**
 * A generic JUnit test which tests {@code putAll} operations on a map. Can't be invoked directly;
 * please see {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
 *
 * @author Chris Povirk
 * @author Kevin Bourrillion
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")