### Exception Handling
```java
import org.codelibs.core.exception.*;

// Runtime exception wrappers eliminate try-catch boilerplate
try {
    // Code that might throw checked exceptions
    return ClassUtil.newInstance(className); // Wraps checked exceptions automatically
} catch (ClassNotFoundRuntimeException e) {
    // Handle the wrapped exception
    logger.error("Class not found: " + className, e);
}
```

     * references is {@code true} and both wrappers use the {@link Object#equals(Object) same}
     * equivalence.
     */
    @Override
    public boolean equals(@Nullable Object obj) {
      if (obj == this) {
        return true;
      }
      if (obj instanceof Wrapper) {
        Wrapper<?> that = (Wrapper<?>) obj; // note: not necessarily a Wrapper<T>

import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Test suites for wrappers in {@code Maps}.
 *
 * @author Louis Wasserman
 */
@NullUnmarked
@AndroidIncompatible // test-suite builders
public class MapsCollectionTest extends TestCase {
  public static Test suite() {

import java.util.TreeSet;
import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import org.jspecify.annotations.NullUnmarked;

/**
 * Run collection tests on wrappers from {@link Multimaps}.
 *
 * @author Jared Levy
 */
@GwtIncompatible // suite // TODO(cpovirk): set up collect/gwt/suites version
@NullUnmarked
@AndroidIncompatible // test-suite builders

import java.util.TreeSet;
import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import org.jspecify.annotations.NullUnmarked;

/**
 * Run collection tests on wrappers from {@link Multimaps}.
 *
 * @author Jared Levy
 */
@GwtIncompatible // suite // TODO(cpovirk): set up collect/gwt/suites version
@NullUnmarked
@AndroidIncompatible // test-suite builders

   * single-threaded.
   */
  @GwtIncompatible // GWT is single threaded
  public void testCopyOf_threadSafe() {
    /*
     * The actual collections that we pass as inputs will be wrappers around these, so
     * ImmutableSet.copyOf won't short-circuit because it won't see an ImmutableSet input.
     */
    ImmutableList<ImmutableSet<String>> distinctCandidatesByAscendingSize =
        ImmutableList.of(

      implements CycleDetectingLock {

    // These ReadLock/WriteLock implementations shadow those in the
    // ReentrantReadWriteLock superclass. They are simply wrappers around the
    // internal Sync object, so this is safe since the shadowed locks are never
    // exposed or used.
    private final CycleDetectingReentrantReadLock readLock;

   * <p>A subcollection, such as a sublist, contains some of the values for a given key. Its
   * ancestor field points to the full wrapped collection with all values for the key. The
   * subcollection {@code refreshIfEmpty}, {@code removeIfEmpty}, and {@code addToMap} methods call
   * the corresponding methods of the full wrapped collection.
   */
  @WeakOuter
  class WrappedCollection extends AbstractCollection<V> {

import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Test suites for wrappers in {@code Maps}.
 *
 * @author Louis Wasserman
 */
@NullUnmarked
@AndroidIncompatible // test-suite builders
public class MapsCollectionTest extends TestCase {
  public static Test suite() {

      implements CycleDetectingLock {

    // These ReadLock/WriteLock implementations shadow those in the
    // ReentrantReadWriteLock superclass. They are simply wrappers around the
    // internal Sync object, so this is safe since the shadowed locks are never
    // exposed or used.
    private final CycleDetectingReentrantReadLock readLock;