[<a href="#Go_1.27">Go 1.27</a>] for a (possibly promoted) field
	    of the struct; the key selects that field.
	</li>
	<li>The types of the embedded fields (if any) <a href="#Selectors">traversed</a>
	    to reach a selected field must not be pointer types.
	</li>
	<li>A key must not denote a promoted field inside an embedded struct if
	    that struct is also specified by another key.
	</li>

 */
package org.codelibs.core.io;

/**
 * Object representing a collection of classes or resources.
 *
 * @author koichik
 * @see TraversalUtil
 */
public interface Traverser {

    /**
     * Returns <code>true</code> if the class file corresponding to the specified class name exists in the resources handled by this instance.
     * <p>

   */
  private static <N> Iterable<N> getReachableNodes(
      Graph<N> graph, N node, TransitiveClosureSelfLoopStrategy strategy) {
    Traverser<N> traverser = Traverser.forGraph(graph);
    switch (strategy) {
      case ADD_SELF_LOOPS_ALWAYS: // always include 'node'
        return traverser.breadthFirst(node);
      case ADD_SELF_LOOPS_FOR_CYCLES: // include 'node' iff there's an incident cycle

        final Traverser[] traversers = TraversalUtil.getTraversers("org.codelibs.core.io.xxx");
        assertThat(traversers, is(notNullValue()));
        assertThat(traversers.length, is(1));

        final Traverser traverser = traversers[0];
        assertThat(traverser instanceof FileSystemTraverser, is(true));

        assertThat(traverser.isExistClass("DummyTest"), is(true));

		h.mutex.Lock()
		h.endTime = UTCNow()
		h.currentStatus.Summary = healFinishedStatus
		h.mutex.Unlock()

		// drain traverse channel so the traversal
		// go-routine does not leak.
		go func() {
			// Eventually the traversal go-routine closes
			// the channel and returns, so this go-routine
			// itself will not leak.
			<-h.traverseAndHealDoneCh
		}()
	}
}

 */
public abstract class TraversalUtil {

    /**
     * Do not instantiate.
     */
    protected TraversalUtil() {
    }

    /** An empty array of {@link Traverser}. */
    protected static final Traverser[] EMPTY_ARRAY = new Traverser[0];

    private static final Logger logger = Logger.getLogger(TraversalUtil.class);

    /** Mapping from URL protocol (as key) to {@link TraverserFactory} (as value). */

import org.eclipse.aether.collection.DependencyTraverser;
import org.eclipse.aether.graph.Dependency;

import static java.util.Objects.requireNonNull;

/**
 * A dependency traverser that excludes the dependencies of fat artifacts from the traversal. Fat artifacts are
 * artifacts that have the property {@link MavenArtifactProperties#INCLUDES_DEPENDENCIES} set to
 * {@code true}.
 *

SequencedCollection<String> sequenced = CollectionsUtil.newLinkedHashSet();
String first = CollectionsUtil.getFirst(sequenced);
String last = CollectionsUtil.getLast(sequenced);
SequencedCollection<String> reversed = CollectionsUtil.reversed(sequenced);

// Specialized collections
LruHashMap<String, Object> lruCache = new LruHashMap<>(100); // LRU cache with max 100 entries
CaseInsensitiveMap<String> configMap = new CaseInsensitiveMap<>();
```

    return checkNotNull(iterable);
  }

  /**
   * Returns a fluent iterable that combines two iterables. The returned iterable has an iterator
   * that traverses the elements in {@code a}, followed by the elements in {@code b}. The source
   * iterators are not polled until necessary.
   *
   * <p>The returned iterable's iterator supports {@code remove()} when the corresponding input

    return checkNotNull(iterable);
  }

  /**
   * Returns a fluent iterable that combines two iterables. The returned iterable has an iterator
   * that traverses the elements in {@code a}, followed by the elements in {@code b}. The source
   * iterators are not polled until necessary.
   *
   * <p>The returned iterable's iterator supports {@code remove()} when the corresponding input