* are responsible for taking the mutex themselves:
   * https://docs.oracle.com/en/java/javase/22/docs/api/java.base/java/util/Collections.html#synchronizedCollection(java.util.Collection)
   *
   * Similarly, we avoid having those methods *implemented* in terms of *other* TestSet methods
   * that will perform holdsLock assertions:
   *
   * - For iterator(), we can accomplish that by not overriding iterator() at all. That way, we

    @Override
    public BigInteger apply(Integer from) {
      BigInteger v = BigInteger.valueOf(from);
      // Math.sin is very slow for values outside 4*pi
      // Need to take absolute value to avoid inverting the value.
      for (double i = 0; i < 100; i += 20) {
        v =
            v.add(
                v.multiply(
                    BigInteger.valueOf(((Double) Math.abs(Math.sin(i) * 10.0)).longValue())));

import org.apache.maven.toolchain.model.ToolchainModel;
import org.slf4j.Logger;

/**
 * Default abstract toolchain implementation, to be used as base class for any toolchain implementation
 * to avoid rewriting usual code.
 *
 * @since 2.0.9
 * @deprecated Use {@link org.apache.maven.api.Toolchain} instead.
 */
@Deprecated(since = "4.0.0")
public abstract class DefaultToolchain // should have been AbstractToolchain...

        EventType type = success ? EventType.AUTHENTICATION_SUCCESS : EventType.AUTHENTICATION_FAILURE;
        Severity severity = success ? Severity.INFO : Severity.WARNING;

        // Pre-mask sensitive data to avoid repeated processing
        String maskedUsername = maskSensitiveData ? maskUsername(username) : username;
        String maskedAddress = maskSensitiveData ? maskIpAddress(remoteAddress) : remoteAddress;

import java.util.Spliterators;
import org.jspecify.annotations.Nullable;

/**
 * A {@link Collection} whose contents will never change, and which offers a few additional
 * guarantees detailed below.
 *
 * <p><b>Warning:</b> avoid <i>direct</i> usage of {@link ImmutableCollection} as a type (just as
 * with {@link Collection} itself). Prefer subtypes such as {@link ImmutableSet} or {@link

            .createTestSuite());
    /*
     * TODO(cpovirk): the Map tests duplicate most of this effort by using a
     * CollectionTestSuiteBuilder on values(). It would be nice to avoid that
     */
    derived.add(
        SetTestSuiteBuilder.using(
                new BiMapValueSetGenerator<K, V>(parentBuilder.getSubjectGenerator()))

    assertEquals(0, cms.count("a"));
    assertTrue(cms.removeExactly("b", 2));
    assertEquals(1, cms.count("b"));
  }

  public void testIteratorRemove_actualMap() {
    // Override to avoid using mocks.
    multiset = ConcurrentHashMultiset.create();

    multiset.add(KEY);
    multiset.add(KEY + "_2");
    multiset.add(KEY);

    int mutations = 0;

        private final ModelBuilder.ModelBuilderSession modelBuilderSession;
        private final Map<String, MavenProject> projectIndex = new ConcurrentHashMap<>(256);

        // Store computed repositories per project to avoid leakage between projects
        private final Map<String, List<ArtifactRepository>> projectRepositories = new ConcurrentHashMap<>();

        /**

2. Write implementation following existing patterns
3. Add comprehensive tests
4. Run `mvn formatter:format license:format test`
5. Update JavaDoc for changed/new classes

**Principles:**
- Avoid over-engineering - keep solutions simple
- Only expose necessary public APIs
- Validate parameters with `Objects.requireNonNull()`
- Provide detailed error messages with context
- Add logging with contextual information

    if (connections == null) {
      return false;
    }

    // Since views are returned, we need to copy the edges that will be removed.
    // Thus we avoid modifying the underlying view while iterating over it.
    for (E edge : ImmutableList.copyOf(connections.incidentEdges())) {
      removeEdge(edge);
    }
    nodeConnections.remove(node);
    return true;
  }