@GwtCompatible
abstract class CommonPattern {
  public abstract CommonMatcher matcher(CharSequence t);

  public abstract String pattern();

  public abstract int flags();

  // Re-declare this as abstract to force subclasses to override.
  @Override
  public abstract String toString();

  public static CommonPattern compile(String pattern) {
    return Platform.compilePattern(pattern);
  }

  public static boolean isPcreLike() {

import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import org.jspecify.annotations.Nullable;

/**
 * An abstract {@code ScheduledExecutorService} that allows subclasses to {@linkplain
 * #wrapTask(Callable) wrap} tasks before they are submitted to the underlying executor.
 *
 * <p>Note that task wrapping may occur even if the task is never executed.
 *
 * @author Luke Sandberg
 */

  /**
   * Constructor for use by subclasses. This hasher instance will process chunks of the specified
   * size.
   *
   * @param chunkSize the number of bytes available per {@link #process(ByteBuffer)} invocation;
   *     must be at least 4
   */
  protected AbstractStreamingHasher(int chunkSize) {
    this(chunkSize, chunkSize);
  }

  /**

/**
 * Base class for implementing services that can handle {@link #doStart} and {@link #doStop}
 * requests, responding to them with {@link #notifyStarted()} and {@link #notifyStopped()}
 * callbacks. Its subclasses must manage threads manually; consider {@link
 * AbstractExecutionThreadService} if you need only a single execution thread.
 *
 * @author Jesse Wilson
 * @author Luke Sandberg
 * @since 1.0
 */
@GwtIncompatible

 * @since 10.0 (<a href="https://github.com/google/guava/wiki/Compatibility">mostly
 *     source-compatible</a> since 9.0)
 */
@GwtCompatible
public abstract class Ticker {
  /** Constructor for use by subclasses. */
  protected Ticker() {}

  /** Returns the number of nanoseconds elapsed since this ticker's fixed point of reference. */
  public abstract long read();

  /**

import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import org.jspecify.annotations.Nullable;

/**
 * An abstract {@code ScheduledExecutorService} that allows subclasses to {@linkplain
 * #wrapTask(Callable) wrap} tasks before they are submitted to the underlying executor.
 *
 * <p>Note that task wrapping may occur even if the task is never executed.
 *
 * @author Luke Sandberg
 */

 * @author Sven Mawson
 * @since 15.0
 */
@GwtCompatible
@SuppressWarnings("EscapedEntity") // We do mean for the user to see "<" etc.
public abstract class CharEscaper extends Escaper {
  /** Constructor for use by subclasses. */
  protected CharEscaper() {}

  /**
   * Returns the escaped form of a given literal string.
   *
   * @param string the literal string to be escaped
   * @return the escaped form of {@code string}

 * This class handles the registration of rules with the {@link RuleManager}
 * and provides getter and setter methods for common properties such as
 * {@code ruleId} and {@code responseProcessor}.
 * </p>
 *
 * <p>
 * Subclasses should extend this class and implement the abstract methods
 * defined in the {@link Rule} interface to provide specific rule logic.
 * </p>
 *
 */
public abstract class AbstractRule implements Rule {

 * doEquivalent and doHash methods to indicate that the parameter cannot be null.
 */
@SuppressWarnings("UngroupedOverloads")
public abstract class Equivalence<T> {
  /** Constructor for use by subclasses. */
  protected Equivalence() {}

  /**
   * Returns {@code true} if the given objects are considered equivalent.
   *
   * <p>This method describes an <i>equivalence relation</i> on object references, meaning that for

import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertTrue;

/**
 * MavenMerger is based on same instances, subclasses should override KeyComputer per type
 */
class MavenMergerTest {
    private MavenMerger mavenMerger = new MavenMerger();

    @Test
    void mergeArtifactId() {