Iterable<Character> result = Traverser.forGraph(graph).breadthFirst('a');

    assertEqualCharNodes(Iterables.limit(result, 2), "ab");
    assertThat(graph.requestedNodes).containsExactly('a', 'a', 'b');

    // Iterate again to see if calculation is done again
    assertEqualCharNodes(Iterables.limit(result, 2), "ab");
    assertThat(graph.requestedNodes).containsExactly('a', 'a', 'a', 'b', 'b');
  }

  @Test

        return dataHelper.getAccessResultList(url);
    }

    /**
     * Iterates over all access results for the specified session.
     *
     * @param sessionId the session ID
     * @param accessResultCallback the callback to invoke for each access result
     */
    @Override
    public void iterate(final String sessionId, final AccessResultCallback<AccessResultImpl<Long>> accessResultCallback) {

public interface AccessResultCallback<RESULT extends AccessResult<?>> {
    /**
     * Processes the given access result.
     *
     * @param accessResult the result of the access operation to be processed
     */
    void iterate(RESULT accessResult);

    };
  }

  /**
   * Uses a hash table to map keys to value collections.
   *
   * <p>The collections returned by {@link Multimap#keySet()}, {@link Multimap#keys()}, and {@link
   * Multimap#asMap()} will iterate through the keys in the order that they were first added to the
   * multimap, save that if all values associated with a key are removed and then the key is added

```java
DataService ds = container.getComponent("dataService");

// Count
int count = ds.getCount(sessionId);

// Get by URL
AccessResult result = ds.getAccessResult(sessionId, url);

// Iterate all
ds.iterate(sessionId, accessResult -> {
    System.out.println(accessResult.getUrl());
    System.out.println(accessResult.getContent());
});

// Cleanup
ds.delete(sessionId);
```

    }

    /**
     * Iterates through all access results for a session, calling the callback for each result.
     * Uses OpenSearch scroll API for efficient iteration over large result sets.
     *
     * @param sessionId The session ID.
     * @param callback The callback to execute for each access result.
     */
    @Override

                assertTrue(urlQueue.getUrl() + "=>" + url2, urlQueue.getUrl().startsWith(url2));
            }

            dataService.iterate(sessionId1, accessResult -> assertTrue(accessResult.getUrl().startsWith(url1)));
            dataService.iterate(sessionId2, accessResult -> assertTrue(accessResult.getUrl().startsWith(url2)));

            dataService.delete(sessionId1);
            dataService.delete(sessionId2);

                assertTrue(urlQueue.getUrl().startsWith(url2));
            }

            dataService.iterate(sessionId1, accessResult -> {
                assertTrue(accessResult.getUrl().startsWith(url1));
                assertEquals(Constants.GET_METHOD, accessResult.getMethod());
            });
            dataService.iterate(sessionId2, accessResult -> {
                assertTrue(accessResult.getUrl().startsWith(url2));

```

## Data Access and Storage

### Accessing Crawled Data

```java
// Get data service
DataService dataService = container.getComponent("dataService");

// Iterate through crawled data
dataService.iterate(sessionId, accessResult -> {
    System.out.println("URL: " + accessResult.getUrl());
    System.out.println("Status: " + accessResult.getHttpStatusCode());

            @Override
            public List<AccessResult<?>> getAccessResultList(String url, boolean hasData) {
                return null;
            }

            @Override
            public void iterate(String sessionId, AccessResultCallback<AccessResult<?>> callback) {
            }
        };

        CrawlingParameterUtil.setDataService(service);

        // Verify it can be retrieved