+ " GraphBuilder)")
public abstract class Traverser<N> {
  private final SuccessorsFunction<N> successorFunction;

  private Traverser(SuccessorsFunction<N> successorFunction) {
    this.successorFunction = checkNotNull(successorFunction);
  }

  /**
   * Creates a new traverser for the given general {@code graph}.
   *
   * <p>Traversers created using this method are guaranteed to visit each node reachable from the

 */
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>

        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));

    assertEqualCharNodes(traverser.breadthFirst(charactersOf("acdb")), "acdb");
    assertEqualCharNodes(traverser.breadthFirst(charactersOf("db")), "db");
  }

  @Test
  public void forGraph_breadthFirst_multiGraph() {
    Traverser<Character> traverser = Traverser.forGraph(MULTI_GRAPH);
    assertEqualCharNodes(traverser.breadthFirst('a'), "abcd");

 */
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). */

 * // won't work
 * TreeTraverser<NodeType> traverser = node -> node.getChildNodes();
 * }
 *
 * Instead, you can pass a lambda expression to the {@code using} factory method:
 *
 * {@snippet :
 * TreeTraverser<NodeType> traverser = TreeTraverser.using(node -> node.getChildNodes());
 * }
 *
 * @author Louis Wasserman
 * @since 15.0
 * @deprecated Use {@link com.google.common.graph.Traverser} instead. All instance methods have

    int dotIndex = fileName.lastIndexOf('.');
    return (dotIndex == -1) ? fileName : fileName.substring(0, dotIndex);
  }

  /**
   * Returns a {@link Traverser} instance for the file and directory tree. The returned traverser
   * starts from a {@link File} and will return all files and directories it encounters.
   *
   * <p><b>Warning:</b> {@code File} provides no support for symbolic links, and as such there is no

   */
  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

            traverseFileSystem(packageDir, rootPackage, handler);
        }
    }

    /**
     * Traverses classes contained in a Jar file.
     * <p>
     * If the specified Jar file has the extension <code>.war</code>, only entries whose path starts with the prefix <code>WEB-INF/classes</code> are traversed.

        assertArgumentNotNull("handler", handler);

        forEach(rootDir, null, handler);
    }

    /**
     * Traverses resources contained in the file system.
     * <p>