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));

            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.

 * // 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

 * // 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

 */
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>

        assertArgumentNotNull("handler", handler);

        forEach(rootDir, null, handler);
    }

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

import java.util.AbstractMap.SimpleImmutableEntry;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@code Entry} for {@link ImmutableMap} that adds extra methods to traverse hash
 * buckets for the key and the value. This allows reuse in {@link RegularImmutableMap} and {@link
 * RegularImmutableBiMap}, which don't have to recopy the entries created by their {@code Builder}
 * implementations.
 *