String testValue = "HELLO WORLD";
        OptionalEntity<String> result = OptionalUtil.ofNullable(testValue);

        assertTrue(result.isPresent());

        // Test that we can chain operations
        String processed = result.map(s -> s.toLowerCase()).orElse("default");

        assertEquals("hello world", processed);

        // Test with null value
        String nullValue = null;

 * local IP addresses. Requests made to `127.0.0.1` will reach the IPv4 server, and requests made to
 * `::1` will reach the IPv6 server.
 *
 * By orchestrating two different servers with the same port but different IP addresses, we can
 * test what OkHttp does when both are reachable, or if only one is reachable.
 *
 * This test only runs on host machines that have both IPv4 and IPv6 addresses for localhost.
 */
@Timeout(30)
class FastFallbackTest {

  // TODO: test adding element of wrong type

  /**
   * Returns {@link Method} instances for the {@code setCount()} tests that assume multisets support
   * duplicates so that the test of {@code Multisets.forSet()} can suppress them.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static List<Method> getSetCountDuplicateInitializingMethods() {
    return asList(

 * constant time operations. Expected in the hashtable sense (depends on the hash function doing a
 * good job of distributing the elements to the buckets to a distribution not far from uniform), and
 * amortized since some operations can trigger a hash table resize.
 *
 * <p>This implementation consumes significantly less memory than {@code java.util.LinkedHashSet} or
 * even {@code java.util.HashSet}, and places considerably less load on the garbage collector. Like

   */
  private void assertSuppressed(Suppression... expected) {
    assertEquals(ImmutableList.copyOf(expected), suppressor.suppressions);
  }

  // TODO(cpovirk): Just use addSuppressed+getSuppressed now that we can rely on it.
  /** Suppressor that records suppressions. */
  private static class TestSuppressor implements Closer.Suppressor {

    private final List<Suppression> suppressions = new ArrayList<>();

    @Override

 * constant time operations. Expected in the hashtable sense (depends on the hash function doing a
 * good job of distributing the elements to the buckets to a distribution not far from uniform), and
 * amortized since some operations can trigger a hash table resize.
 *
 * <p>This implementation consumes significantly less memory than {@code java.util.LinkedHashSet} or
 * even {@code java.util.HashSet}, and places considerably less load on the garbage collector. Like

/*
 * © 2025 CodeLibs, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of

/*
 * © 2025 CodeLibs, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * multiplexing requests. It encapsulates a stream and some protocol
 * knowledge (provided by a concrete subclass) so that connecting,
 * disconnecting, sending, and receiving can be syncronized
 * properly. Apparatus is provided to send and receive requests
 * concurrently.
 */

public abstract class Transport implements Runnable {

    /**
     * Default constructor for Transport.

            // Register the command with the new processor
            PrefixQueryCommand newCommand = new PrefixQueryCommand();
            newCommand.register();

            // Verify that the command can process PrefixQuery by executing it
            PrefixQuery query = new PrefixQuery(new Term("field", "test"));
            QueryContext context = new QueryContext("test", false);